Patent Publication Number: US-8111155-B2

Title: Detection and control of pests

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 11/605,009 (filed 31 May 2007) now U.S. Pat. No. 7,719,429 which is a divisional of U.S. patent application Ser. No. 10/406,121 (filed 3 Apr. 2003), now U.S. Pat. No. 7,212,112 which is a continuation of International Patent Application Number PCT/US02/24186 (filed 31 Jul. 2002), which is a continuation-in-part of U.S. patent application Ser. No. 10/103,460 (filed 21 Mar. 2002), now U.S. Pat. No. 7,212,129 which is a continuation-in-part of U.S. patent application Ser. No. 09/925,392 (filed 9 Aug. 2001), now U.S. Pat. No. 7,262,702 which is a continuation-in-part of International Patent Application Number PCT/US00/26373 (filed 25 Sep. 2000 and published in English 4 Apr. 2002) and U.S. patent application Ser. No. 09/669,316 (filed 25 Sep. 2000), now U.S. Pat. No. 6,724,312 both of which are a continuation-in-part of International Patent Application Number PCT/US99/16519 (filed 21 Jul. 1999 and published in English 1 Feb. 2001). 
    
    
     BACKGROUND 
     The present invention relates to data gathering and sensing techniques, and more particularly, but not exclusively, relates to techniques for gathering data from one or more pest control devices. 
     The removal of pests from areas occupied by humans, livestock, and crops has long been a challenge. Pests of frequent concern include various types of insects and rodents. Subterranean termites are a particularly troublesome type of pest with the potential to cause severe damage to wooden structures. Various schemes have been proposed to eliminate termites and certain other harmful pests of both the insect and noninsect variety. In one approach, pest control relies on the blanket application of chemical pesticides in the area to be protected. However, as a result of environmental regulations, this approach is becoming less desirable. 
     Recently, advances have been made to provide for the targeted delivery of pesticide chemicals. U.S. Pat. No. 5,815,090 to Su is one example. Another example directed to termite control is the SENTRICON™ system of Dow AgroSciences that has a business address of 9330 Zionsville Road, Indianapolis, Ind. In this system, a number of units each having a termite edible material, are placed in the ground about a dwelling to be protected. The units are inspected routinely by a pest control service for the presence of termites, and inspection data is recorded with reference to a unique barcode label associated with each unit. If termites are found in a given unit, a bait is installed that contains a slow-acting pesticide intended to be carried back to the termite nest to eradicate the colony. 
     However, techniques for more reliably and/or cost-effectively sensing the activity of termites or other pests are desired. Alternatively or additionally, the ability to gather more comprehensive data relating to pest behavior is sought. Thus, there is a continuing demand for further advancement in the area of pest control and related sensing technologies. 
     SUMMARY 
     One embodiment of the present invention includes a unique sensing technique applicable to the control of pests. In another embodiment, a unique technique to gather data concerning pest activity is provided. A further embodiment includes a unique pest control device to detect and exterminate one or more selected species of pest. As used herein, a “pest control device” refers broadly to any device that is used to sense, detect, monitor, bait, feed, poison, or exterminate one or more species of pest. 
     Another embodiment of the present invention includes a unique pest control system. This system includes a number of pest control devices and an apparatus to gather data from the pest control devices. In one embodiment, the apparatus communicates with the pest control devices using wireless techniques and can also be arranged to locate the devices. The pest control devices can be of different types, at least some of which are configured to provide information relating to different levels of pest activity in addition to an indication of whether pests are present or not. 
     Still another embodiment of the present invention includes a pest control device with a circuit including one or more sensing elements operable to be consumed or displaced by one or more pests. This circuit monitors an electrical and/or magnetic property of the one or more sensing elements that is indicative of different nonzero levels of pest consumption or displacement. 
     In still another embodiment, a sensor includes one or more portions operable to be separated or removed from each other and a circuit operable to monitor a property corresponding to electrical capacitance that changes with removal or separation of the one or more portions from the sensor. This separation or removal can occur due to consumption or displacement by pests; wear, erosion, or abrasion by mechanical means, and/or a chemical reaction. Accordingly, the sensor can be used to monitor various pest activities, mechanical operations, and chemical alterations to name only a few. 
     For a further embodiment of the present invention, one or more pest control devices are installed that each include a respective bait for one or more species of pest, a respective pest sensor, and respective communicative circuitry coupled to the respective pest sensor. A stimulus is provided to one of the pest control devices to activate the respective communication circuitry. In response to the stimulus, status information about the respective pest sensor is received. 
     For still a further embodiment, a pest control device includes a bait operable to be consumed or displaced by one or more species of pest, a pest sensing circuit, and a monitoring circuit to monitor status of the pest sensing member. The monitoring circuit includes one or more indicators and a device responsive to a magnetic field to provide information about the pest sensing circuit with the one or more indicators. 
     Another embodiment of the present invention includes: installing a pest control device including a bait, a pest sensing member, and a monitoring circuit to monitor status of the pest sensing member; applying a magnetic field to the pest control device to stimulate operation of the monitoring circuit; and providing information about the pest sensing member from the monitoring circuit in response to the applied magnetic field. In one form, the pest control device includes one or more visual indicators to provide the information. Alternatively or additionally, the magnetic field can be applied externally using an operator-controlled wand or the like and the monitoring circuit includes a magnetic switch responsive to the magnetic field. 
     One object of the present invention is to provide a unique sensing technique applicable to the control of pests. 
     Another object of the present invention is to provide a unique method, system, device or apparatus to gather data concerning pest activity and/or detect and exterminate one or more species of pest. 
     Other embodiments, forms, aspects, features, and objects of the present invention shall become apparent from the drawings and description contained herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic view of a first type of pest control system according to the present invention that includes several of a first type of pest control device. 
         FIG. 2  is a view of selected elements of the system of  FIG. 1  in operation. 
         FIG. 3  is an exploded, partial sectional view of a pest monitoring assembly of the first type of pest control device. 
         FIG. 4  is an exploded, partial sectional view of the pest monitoring assembly of  FIG. 3  along a view plane perpendicular to the view plane of  FIG. 3 . 
         FIG. 5  is a partial, top view of a portion of a communication circuit subassembly of the pest monitoring assembly shown in  FIGS. 3 and 4 . 
         FIG. 6  is an exploded assembly view of the first type of pest control device with the pest monitoring assembly of  FIG. 3 . 
         FIG. 7  is an exploded assembly view of the first type of pest control device with a pesticide delivery assembly in place of the pest monitoring assembly of  FIG. 3 . 
         FIG. 8  is a schematic view of selected circuitry of the system of  FIG. 1 . 
         FIG. 9  is a schematic view of circuitry for the pest monitoring assembly of  FIG. 3 . 
         FIG. 10  is a flowchart of one example of a process of the present invention that may be performed with the system of  FIG. 1 . 
         FIG. 11  is a diagrammatic view of a second type of pest control system according to the present invention that includes a second type of pest control device. 
         FIG. 12  is an exploded, partial assembly view of the second type of pest control device. 
         FIG. 13  is an end view of an assembled sensor of the second type of pest control device. 
         FIG. 14  is a diagrammatic view of a third type of pest control system according to the present invention that includes a third type of pest control device. 
         FIG. 15  is a partial cutaway view of a sensor for the third type of pest control device. 
         FIG. 16  is a sectional view of the sensor for the third type of pest control device taken along the section line  16 - 16  shown in  FIG. 15 . 
         FIG. 17  is a diagrammatic view of a fourth type of pest control system according to the present invention that includes a fourth type of pest control device. 
         FIG. 18  is a partial cutaway view of a sensor for the fourth type of pest control device. 
         FIG. 19  is a sectional view of the sensor for the fourth type of pest control device taken along the section line  19 - 19  shown in  FIG. 18 . 
         FIG. 20  is a diagrammatic view of a fifth type of pest control system according to the present invention that includes pest control devices of the second, third, and fourth types, and further includes a fifth type of pest control device. 
         FIG. 21  is a diagrammatic view of a sixth type of pest control system according to the present invention that includes a sixth type of pest control device. 
         FIG. 22  is a diagrammatic view of a seventh type of pest control system according to the present invention that includes a seventh type of pest control device. 
         FIG. 23  is a partial diagrammatic, sectional view of an eighth type of pest control device according to the present invention. 
         FIG. 24  is a schematic view of circuitry for the eighth type of pest control device of  FIG. 23 . 
         FIG. 25  is a partial diagrammatic, sectional view of a ninth type of pest control system according to the present invention. 
         FIG. 26  is a schematic view of circuitry for a ninth type of pest control device included in the system of  FIG. 25 . 
         FIG. 27  is a partial diagrammatic, sectional view of a tenth type of pest control system according to the present invention. 
         FIG. 28  is a schematic view of circuitry for a tenth type of pest control device included in the system of  FIG. 27 . 
         FIG. 29  is a partial diagrammatic view of an eleventh type of pest control system according to the present invention. 
         FIG. 30  is a partial diagrammatic view of an eleventh type of pest control device included in the system of  FIG. 29 . 
         FIG. 31  is a schematic view of circuitry for the eleventh type of pest control system of  FIG. 29 . 
         FIG. 32  is a flowchart of one example of a procedure of the present invention that may be performed with one or more different types of the pest control devices. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. 
       FIG. 1  illustrates pest control system  20  of one embodiment of the present invention. System  20  is arranged to protect building  22  from damage due to pests, such as subterranean termites. System  20  includes a number of pest control devices  110  positioned about building  22 . In  FIG. 1 , only a few of devices  110  are specifically designated by reference numerals to preserve clarity. System  20  also includes interrogator  30  to gather information about devices  110 . Data gathered from devices  110  with interrogator  30  is collected in Data Collection Unit (DCU)  40  through communication interface  41 . 
     Referring additionally to  FIG. 2 , certain aspects of the operation of system  20  are illustrated. In  FIG. 2 , a pest control service provider P is shown operating interrogator  30  to interrogate pest control devices  110  located at least partially below ground G using a wireless communication technique. In this example, interrogator  30  is shown in a hand-held form convenient for sweeping over ground G to establish wireless communication with installed devices  110 . Additional aspects of system  20  and its operation are described in connection with  FIGS. 8-10 , but first further details concerning a representative pest control device  110  are described with reference to  FIGS. 3-7 . 
       FIGS. 3-7  illustrates various features of pest control device  110 . To initially detect pests, pest control device  110  is internally configured with pest monitoring assembly  112 . Referring more specifically to  FIGS. 3 and 4 , pest monitoring assembly  112  is illustrated along centerline assembly axis A. Axis A coincides with the view planes of both  FIGS. 3 and 4 ; where the view plane of  FIG. 4  is perpendicular to the view plane of  FIG. 3 . 
     Pest monitoring assembly  112  includes sensor subassembly  114  below communication circuit subassembly  116  along axis A. Sensor subassembly  114  includes two (2) bait members  132  (see  FIGS. 3 and 6 ). Bait members  132  are each made from a bait material for one or more selected species of pests. For example, bait members  132  can each be made of a material that is a favorite food of such pests. In one example directed to subterranean termites, bait members  132  are each in the form of a soft wood block without a pesticide component. In other examples for termites, one or more of bait members  132  can include a pesticide, have a composition other than wood, or a combination of these features. In still other examples where pest control device  110  is directed to a type of pest other than termites, a correspondingly different composition of each bait member  132  is typically used. 
     Sensor subassembly  114  also includes sensor  150 . Sensor  150  is depicted between bait members  132  in  FIGS. 3 and 6 ; where  FIG. 6  is a more fully assembled view of pest control device  110  than  FIG. 3 . Sensor  150  is generally elongated and has end portion  152   a  opposite end portion  152   b  as shown in  FIGS. 4 and 6 . A middle portion of sensor  150  is represented by a pair of adjacent break lines separating portions  152   a  and  152   b  in  FIG. 4 , and bait members  132  are not shown in  FIG. 4  to prevent obscuring the view of sensor  150 . 
     Sensor  150  includes substrate  151 . Substrate  151  carries conductor  153  that is arranged to provide sensing element  153   a  in the form of an electrically conductive loop or pathway  154  shown in the broken view of  FIG. 4 . Along the middle sensor portion represented by the break lines of  FIG. 4 , the four segments of pathway  154  continue along a generally straight, parallel route (not shown), and correspondingly join the four pathway segments of end portion  152   a  ending at one of the break lines with the four pathway segments of end portion  152   b  ending at another of the break lines. Pathway  154  terminates with a pair of electrical contact pads  156  adjacent substrate edge  155  of end portion  152   a.    
     Substrate  151  and/or conductor  153  are/is comprised of one or more materials susceptible to consumption or displacement by the pests being monitored with pest monitoring assembly  112 . These materials can be a food substance, a nonfood substance, or a combination of both for the one or more pest species of interest. Indeed, it has been found that materials composed of nonfood substances will be readily displaced during the consumption of adjacent edible materials, such as bait members  132 . As substrate  151  or conductor  153  are consumed or displaced, pathway  154  is eventually altered. This alteration can be utilized to indicate the presence of pests by monitoring one or more corresponding electrical properties of pathway  154  as will be more fully described hereinafter. Alternatively, substrate  151  and/or conductor  153  can be oriented with respect to bait members  132  so that a certain degree of consumption or displacement of bait members  132  exerts a mechanical force sufficient to alter the electrical conductivity of pathway  154  in a detectable manner. For this alternative, substrate  151  and/or conductor  153  need not be directly consumed or displaced by the pest of interest. 
     Pest monitoring assembly  112  further includes circuit subassembly  116  coupled to sensor subassembly  114 . Circuit subassembly  116  is arranged to detect and communicate pest activity as indicated by a change in one or more electrical properties of pathway  154  of sensor subassembly  114 . Circuit subassembly  116  includes circuit enclosure  118  for housing communication circuitry  160  and a pair of connection members  140  for detachably coupling communication circuitry  160  to sensor  150  of sensor subassembly  114 . Various operational aspects of this arrangement are described in connection with  FIGS. 8-10  hereinafter. Enclosure  118  includes cover piece  120 , o-ring  124 , and base  130 , that each have a generally circular outer perimeter about axis A. Enclosure  118  is shown more fully assembled in  FIG. 4  relative to  FIG. 3 . Cover piece  120  defines cavity  122  bounded by inner lip  123 . Base  130  defines channel  131  (shown in phantom) sized to receive o-ring  124  and also includes outer flange  133  configured to engage inner lip  123  when base  130  is assembled with cover piece  120  (see  FIG. 4 ). 
     Communication circuitry  160  is positioned between cover piece  120  and base  130 . Communication circuitry  160  includes coil antenna  162  and printed wiring board  164  carrying circuit components  166 . Referring also to  FIG. 5 , a top view is shown of an assembly of base  130 , connection members  140 , and wireless communication circuitry  160 . In  FIG. 5 , axis A is perpendicular to the view plane and is represented by like labeled cross-hairs. Base  130  includes posts  132  to engage mounting holes through printed wiring board  164 . Base  130  also includes mounts  134  to engage coil antenna  162  and maintain it in fixed relation to base  130  and printed wiring board  164  when assembled together. Base  130  further includes four supports  136  each defining opening  137  therethrough as best illustrated in  FIG. 4 . Base  130  is shaped with a centrally located projection  138  between adjacent pairs of supports  136 . Projection  138  defines recess  139  (shown in phantom in  FIG. 3 ). 
     Referring generally to  FIGS. 3-5 , connection members  140  each include a pair of connection nubs  146 . Each nub  146  has neck portion  147  and head portion  145  that extend from opposing end portions of the respective connection member  140 . For each connection member  140 , projection  148  is positioned between the corresponding pair of nubs  146 . Projection  148  defines recess  149 . Connection members  140  are formed from an electrically conductive, elastimeric material. In one embodiment, each connection member  140  is made from a carbon-containing silicone rubber, such as compound  862  available from TECKNIT, having a business address of 129 Dermody Street, Cranford, N.J. 07016. Nonetheless, in other embodiments, a different composition can be used. 
     To assemble each connection member  140  to base  130 , the corresponding pair of nubs  146  are inserted through a respective pair of openings  137  of supports  136 , with projection  148  extending into recess  139 . Head portion  145  of each of nubs  146  is sized to be slightly larger than the respective opening  137  through which it is to pass. As a result, during insertion, head portions  145  are elastically deformed until fully passing through the respective opening  137 . Once head portion  145  extends through opening  137 , it returns to its original shape with neck  147  securely engaging the opening margin. By appropriate sizing and shaping of head portion  145  and neck portion  147  of nubs  146 , openings  137  can be sealed to resist the passage of moisture and debris when base  130  and connection members  140  are assembled together. As shown in  FIG. 5 , printed wiring board  164  contacts one nub  146  of each connection member  140  after assembly. 
     After connection members  140  are assembled with base  130 , enclosure  118  is assembled by inserting base  130  into cavity  122  with o-ring  124  carried in channel  131 . During insertion, cover piece  120  and/or base  130  elastically deform so that flange  133  extends into cavity  122  beyond inner lip  123 , such that cover piece  120  and base  130  engage each other with a “snap-fit” type of connection. The angled profile of the outer surface of base  130  facilitates this form of assembly. Once cover piece  120  and base  130  are connected in this manner, o-ring  124  provides a resilient seal to resist the intrusion of moisture and debris into cavity  122 . The inner surface of cover piece  120  engaged by base  130  has a complimentary profile that can also assist with sealing. 
     After communication circuit subassembly  116  is assembled, sensor  150  is assembled to subassembly  116  by asserting end portion  152   a  into recess  149  of each connection member  140  carried by base  130 . Connection members  140  are sized to be slightly elastically deformed by the insertion of end portion  152   a  into recess  149 , such that a biasing force is applied by connection members  140  to end portion  152   a  to securely hold sensor  150  in contact therewith. Once end portion  152   a  is inserted into connection members  140 , each pad  156  is electrically contacted by a different one of connection members  140 . In turn, each nub  146  that contacts printed wiring board  164  electrically couples pathway  154  to printed wiring board  164 . 
     Referring to  FIG. 6 , an exploded view of pest control device  110  and pest monitoring assembly  112  is depicted. In  FIG. 6 , sensor subassembly  114  and circuit subassembly  116  are shown assembled together and nested in carrying member  190  to maintain pest monitoring assembly  112  as a unit. Carrying member  190  is in the form of a frame that includes base  192  attached to opposing side members  194 . Only one of side members  194  is fully visible in  FIG. 6 , with the other extending from base  192  along the hidden side of pest monitoring assembly  112  in a like manner. Side members  194  are joined together by bridge  196  opposite base  192 . Bridge  196  is arranged to define a space  198  contoured to receive the assembled enclosure  118  of circuit subassembly  116 . 
     Pest control device  110  includes housing  170  with removable cap  180  arranged for placement in the ground as shown, for example, in  FIG. 2 . Housing  170  defines chamber  172  intersecting opening  178 . Pest monitoring assembly  112  and carrying member  190  are sized for insertion into chamber  172  through opening  178 . Housing  170  has end portion  171   a  opposite end portion  171   b . End portion  171   b  includes tapered end  175  to assist with placement of pest control  110  in the ground as illustrated in  FIG. 2 . End  175  terminates in an aperture (not shown). In communication with chamber  172  are a number of slots  174  defined by housing  170 . Slots  174  are particularly well-suited for the ingress and egress of termites from chamber  172 . Housing  170  has a number of protruding flanges a few of which are designated by reference numerals  176   a ,  176   b ,  176   c ,  176   d , and  176   e  in  FIG. 6  to assist with positioning of pest control device  110  in the ground. 
     Once inside chamber  172 , pest monitoring assembly  112  can be secured in housing  170  with cap  180 . Cap  180  includes downward prongs  184  arranged to engage channels  179  of housing  170 . After cap  180  is fully seated on housing  170 , it can be rotated to engage prongs  184  in a latching position that resists disassembly. This latching mechanism can include a pawl and detent configuration. Slot  182  can be used to engage cap  180  with a tool, such as a flat-bladed screwdriver, to assist in rotating cap  180 . It is preferred that carrying member  190 , base  130 , cover piece  120 , housing  170 , and cap  180  be made of a material resistant to deterioration by expected environmental exposure and resistant to alteration by the pests likely to be detected with pest control device  110 . In one form, these components are made from a polymeric resin like polypropylene or CYCOLAC AR polymeric plastic material available from General Electric Plastics, having a business address of One Plastics Avenue, Pittsfield, Mass. 01201. 
     Typically, pest monitoring assembly  112  is placed in chamber  172  after housing  170  is at least partially installed in the ground in the region to be monitored. Assembly  112  is configured to detect and report pest activity as will be more fully explained in connection with  FIGS. 8-10 . In one mode of operation, pest control device  110  is reconfigured to deliver a pesticide after pest activity is detected with pest monitoring assembly  112 .  FIG. 7  is an exploded assembly view of one example of such a reconfiguration. In  FIG. 7 , pest control device  110  utilizes pesticide delivery assembly  119  as a substitute for pest monitoring assembly  112  after pest activity has been detected. Substitution begins by rotating cap  180  in a direction opposite that required to latch it, and removing cap  180  from housing  170 . Typically, the removal of cap  180  is performed with housing  170  remaining at least partially installed in the ground. Pest monitoring assembly  112  is then extracted from housing  170  by pulling carrying member  190 . It has been found that application of pest control device  110  to pests such as termites can lead to the accumulation of a substantial amount of dirt and debris in chamber  172  before pest monitoring assembly  112  is removed. This accumulation can hamper the removal of pest monitoring assembly  112  from chamber  172 . As a result, member  190  is preferably arranged to withstand at least 40 pounds (lbs.) of pulling force, and more preferably at least 80 lbs. of pulling force. 
     After pest monitoring assembly  112  is removed from chamber  172 , pesticide delivery assembly  119  is placed in chamber  172  of housing  170  through opening  178 . Pesticide delivery assembly  119  includes pesticide bait tube  1170  defining chamber  1172 . Chamber  1172  contains pesticide bearing matrix member  1173 . Tube  1170  has a threaded end  1174  arranged for engagement by cap  1176 , which has complimentary inner threading (not shown). Cap  1176  defines aperture  1178 . Circuit subassembly  116  is detached from sensor  150  before, during, or after removal of pest monitoring assembly  112  from housing  170 . Aperture  1178  is accordingly sized and shaped to securely receive circuit subassembly  116  after disassembly from pest monitoring assembly  112 . After pesticide delivery assembly  119  is configured with circuit subassembly  116 , it is placed in chamber  172 , and cap  180  can re-engage housing  170  in the manner previously described. 
       FIG. 8  schematically depicts circuitry of interrogator  30  and pest monitoring assembly  112  for a representative pest control device  110  of system  20  shown in  FIG. 1 . Monitoring circuitry  169  of  FIG. 8  collectively represents communication circuitry  160  connected to conductor  153  of sensor  150  by connection members  140 . In  FIG. 8 , pathway  154  of monitoring circuitry  169  is represented with a single-pole, single-throw switch corresponding to the capability of sensor  150  to provide a closed or open electrical pathway in accordance with pest activity. Further, communication circuitry  160  includes sensor state detector  163  to provide a two-state status signal when energized; where one state represents an open or high resistance pathway  154  and the other state represents an electrically closed or continuous-pathway  154 . Communication circuit  160  also includes identification code  167  to generate a corresponding identification signal for device  110 . Identification code  167  may be in the form of a predetermined multibit binary code or such other form as would occur to those skilled in the art. 
     Communication circuitry  160  is configured as a passive RF transponder that is energized by an external stimulation or excitation signal from interrogator  30  received via coil antenna  162 . Likewise, detector  163  and code  167  of circuitry  160  are powered by this stimulation signal. In response to being energized by a stimulation signal, communication circuitry  160  transmits information to interrogator  30  with coil antenna  162  in a modulated RF format. This wireless transmission corresponds to the bait status determined with detector  163  and a unique device identifier provided by identification code  167 . 
     Referring additionally to  FIG. 9 , further details of communication circuitry  160  and monitoring circuitry  169  are depicted. In  FIG. 9 , a broken line box represents printed wiring board  164 , circumscribing components  166  that it carries. Circuit components  166  include capacitor C, integrated circuit IC, resistor R, and PNP transistor Q 1 . In the depicted embodiment, integrated circuit IC is a passive, Radio Frequency Identification Device (RFID) model no. MCRF202 provided by Microchip Technologies, Inc of 2355 West Chandler Blvd., Chandler, Ariz. 85224-6199. Integrated circuit IC includes code  167  and detector  163 . 
     IC also includes two (2) antenna connections V A  and V B , that are connected to a parallel network of coil antenna  162  and capacitor C. Capacitor C has a capacitance of about 390 picoFarads (pF), and coil antenna  162  has an inductance of about 4.16 milllHenries (mH) for the depicted embodiment. IC is configured to supply a regulated D.C. electric potential via contacts V CC  and V SS , with V CC  being at a higher potential. This electric potential is derived from the stimulus RF input received with coil antenna  162  via connections V A  and V B . The V CC  connection of IC is electrically coupled to the emitter of transistor Q 1  and one of the electrical contact pads  156  of sensor  150 . The base of transistor Q 1  is electrically coupled to the other of electrical contact pads  156 . Resistor R is electrically connected between the V SS  connection of IC and the base of transistor Q 1 . The collector of transistor Q 1  is coupled to the SENSOR input of IC. When intact, the serially connected electrically conductive pathway  154  and connection members  140  present a relatively low resistance compared to the depicted value of 330 Kilo-ohms for resistor R. Accordingly, the voltage presented at the base of transistor Q 1  by the voltage divider formed by R, connection members  140 , and electrically conductive pathway  154  is not sufficient to turn on transistor Q 1 —instead shunting current through R. As a result, the input SENSOR to IC is maintained at a logic low level relative to V SS  via a pull-down resistor internal to IC (not shown). When the resistance of electrically conductive path  154  increases to indicate an open circuit condition, the potential difference between the emitter and base of transistor Q 1  changes to turn-on transistor Q 1 . In correspondence, the voltage potential provided to the SENSOR input of IC is at a logic level high relative to V SS . The transistor Q 1  and resistor R circuit arrangement has the effect of reversing the logic level provided to the SENSOR input compared to placing electrically conductive pathway  154  directly across V CC  and the SENSOR input. 
     In other embodiments, different arrangements of one or more components may be utilized to collectively or separately provide communication circuitry  160 . In one alternative configuration, communication circuit  160  may transmit only a bait status signal or an identification signal, but not both. In a further embodiment, different variable information about device  110  may be transmitted with or without bait status or device identification information. In another alternative, communication circuit  160  may be selectively or permanently “active” in nature, having its own internal power source. For such an alternative, power need not be derived from an external stimulus signal. Indeed, device  110  could initiate communication instead. In yet another alternative embodiment, device  110  may include both active and passive circuits. 
       FIG. 8  also illustrates communication circuitry  31  of interrogator  30 . Interrogator  30  includes RF excitation circuit  32  to generate RF stimulation signals and RF receiver (RXR) circuit  34  to receive an RF input. Circuits  32  and  34  are each operatively coupled to controller  36 . While interrogator  30  is shown with separate coils for circuits  32  and  34 , the same coil may be used for both in other embodiments. Controller  36  is operatively coupled to Input/Output (I/O) port  37  and memory  38  of interrogator  30 . Interrogator  30  has its own power source (not shown) to energize circuitry  31  that is typically in the form of an electrochemical cell, or battery of such cells (not shown). Controller  36  may be comprised of one or more components. In one example controller  36  is a programmable microprocessor-based type that executes instructions loaded in memory  38 . In other examples, controller  36  may be defined by analog computing circuits, hardwired state machine logic, or other device types as an alternative or addition to programmable digital circuitry. Memory  38  may include one or more solid-state semiconductor components of the volatile or nonvolatile variety. Alternatively or additionally, memory  38  may include one or more electromagnetic or optical storage devices such as a floppy or hard disk drive or a CD-ROM. In one example, controller  36 , I/O port  37 , and memory  38  are integrally provided on the same integrated circuit chip. 
     I/O port  37  is configured to send data from interrogator  30  to data collection unit  40  as shown in  FIG. 1 . Referring back to  FIG. 1 , further aspects of data collection unit  40  are described. Interface  41  of unit  40  is configured for communicating with interrogator  30  via I/O port  37 . Unit  40  also includes processor  42  and memory  44  to store and process information obtained from interrogator  30  about devices  110 . Processor  42  and memory  44  may be variously configured in an analogous manner to that described for controller  36  and memory  38 , respectively. Further, interface  41 , processor  42 , and memory  44  may be integrally provided on the same integrated circuit chip. 
     Accordingly, for the depicted embodiment communication circuitry  160  transmits bait status and identifier information to interrogator  30  when interrogator  30  transmits a stimulation signal to device  110  within range. RF receiver circuit  34  of interrogator  30  receives the information from device  110  and provides appropriate signal conditioning and formatting for manipulation and storage in memory  38  by controller  36 . Data received from device  110  may be transmitted to data collection unit  40  by operatively coupling I/O port  37  to interface  41 . 
     Unit  40  can be provided in the form of a laptop personal computer, hand-held or palm type computer, or other dedicated or general purpose variety of computing device that is adapted to interface with interrogator  30  and programmed to receive and store data from interrogator  30 . In another embodiment, unit  40  may be remotely located relative to interrogator  30 . For this embodiment, one or more interrogators  30  communicate with unit  40  over an established communication medium like the telephone system or a computer network like the internet. In yet another embodiment, interrogator  30  is absent and unit  40  is configured to communicate directly with communication circuitry  160 . Interrogator  30  and/or unit  40  is arranged to communicate with one or more pest control devices through a hardwired interface. In still other embodiments, different interface and communication techniques may be used with interrogator  30 , data collection unit  40 , and devices  110  as would occur to those skilled in the art. 
     In a preferred embodiment directed to subterranean termites, substrate  151  is preferably formed from a nonfood material that is resistant to changes in dimension when exposed to moisture levels expected in an in-ground environment. It has been found that such a dimensionally stable substrate is less likely to cause inadvertent alterations to the electrically conductive pathway  154 . One preferred example of a more dimensionally stable substrate  151  includes a paper coated with a polymeric material, such as polyethylene. Nonetheless, in other embodiments, substrate  151  may be composed of other materials or compounds including those that may change in dimension with exposure to moisture and that may alternatively or additionally include one or more types of material favored as a food by targeted pests. 
     It has been found that in some applications, certain metal-based electrical conductors, such as a silver-containing conductor, tend to readily ionize in aqueous solutions common to the environment in which pest control devices are typically used. This situation can lead to electrical shorting or bridging of the pest control device conductive pathway by the resulting electrolytic solution, possibly resulting in improper device performance. It has also been surprisingly discovered that a carbon-based conductor has a substantially reduced likelihood of electrical shorting or bridging. Accordingly, for such embodiments, pathway  154  is preferably formed from a nonmetallic, carbon-containing ink compound. One source of such ink is the Acheson Colloids Company with a business address of 600 Washington Ave., Port Huron, Mich. Carbon-containing conductive ink comprising conductor  153  can be deposited on substrate  151  using a silk screening, pad printing, or ink jet dispensing technique; or such other technique as would occur to those skilled in the art. 
     Compared to commonly selected metallic conductors, a carbon-based conductor can have a higher electrical resistivity. Preferably, the volume resistivity of the carbon-containing ink compound is greater than or equal to about 0.001 ohm-cm (ohm-centimeter). In a more preferred embodiment, the volume resistivity of conductor  153  comprised of a carbon-containing material is greater than or equal to 0.1 ohm-cm. In a still more preferred embodiment, the volume resistivity of conductor  153  comprised of a carbon-containing material is greater than or equal to about 10 ohms-cm. In yet other embodiments, conductor  153  can have a different composition or volume resistivity as would occur to those skilled in the art. 
     In further embodiments, other electrically conductive elements and/or compounds are contemplated for pest control device conductors that are not substantially subject to ionization in aqueous solutions expected in pest control device environments. In still further embodiments of the present invention, metal-based conductors are utilized notwithstanding the risk of electrical bridging or shorting. 
     Referring generally to  FIGS. 1-9 , certain operational aspects of system  20  are further described. Typically, interrogator  30  is arranged to cause excitation circuit  32  to generate an RF signal suitable to energize circuitry  169  of device  110  when device  110  is within a predetermined distance range of interrogator  30 . In one embodiment, controller  36  is arranged to automatically prompt generation of this stimulation signal on a periodic basis. In another embodiment, the stimulation signal may be prompted by an operator through an operator control coupled to interrogator  30  (not shown). Such operator prompting may be either as an alternative to automatic prompting or as an additional prompting mode. Interrogator  30  may include a visual or audible indicator of a conventional type (not shown) to provide interrogation status to the operator as needed. 
     Referring further to the flowchart of  FIG. 10 , termite control process  220  of a further embodiment of the present invention is illustrated. In stage  222  of process  220 , a number of pest control devices  110  are installed in a spaced apart relationship relative to an area to be protected. By way of nonlimiting example,  FIG. 1  provides a diagram of one possible distribution of a number of devices  110  arranged about building  22  to be protected. One or more of these devices can be at least partially placed below ground as illustrated in  FIG. 2 . 
     For process  220 , devices  110  are initially each installed with a pest monitoring assembly  112  each including a pair of bait members  132  of a monitoring variety that are favored as a food by subterranean termites and do not include a pesticide. It has been found that once a colony of termites establish a pathway to a food source, they will tend to return to this food source. Consequently, devices  110  are initially placed in a monitoring configuration to establish such pathways with any termites that might be in the vicinity of the area or structures desired to be protected, such as building  22 . 
     Once in place, a map of devices  110  is generated in stage  224 . This map includes indicia corresponding to the coded identifiers for installed devices  110 . In one example, the identifiers are unique to each device  110 . Pest monitoring loop  230  of process  220  is next encountered with stage  226 . In stage  226 , installed devices  110  are periodically located and data is loaded from each device  110  by interrogation of the respective wireless communication circuit  160  with interrogator  30 . This data corresponds to bait status and identification information. In this manner, pest activity in a given device  110  may readily be detected without the need to extract or open each device  110  for visual inspection. Further, such wireless communication techniques permit the establishment and building of an electronic database that may be downloaded into data collection device  40  for long term storage. 
     It should also be appreciated that over time, subterranean pest monitoring devices  110  may become difficult to locate as they have a tendency to migrate, sometimes being pushed further underground. Moreover, in-ground monitoring devices  110  may become hidden by the growth of surrounding plants. In one embodiment, interrogator  30  and multiple devices  110  are arranged so that interrogator  30  only communicates with the closest device  110 . This technique may be implemented by appropriate selection of the communication range between interrogator  30  and each of devices  110 , and the position of devices  110  relative to each other. Accordingly, interrogator  30  may be used to scan or sweep a path along the ground to consecutively communicate with each individual device  110 . For such embodiments, the wireless communication subsystem  120  provided by interrogator  30  with each of devices  110  provides a procedure and means to more reliably locate a given device  110  after installation as opposed to more limited visual or metal detection approaches. Indeed, this localization procedure may be utilized in conjunction with the unique identifier of each device and/or the map generated in stage  224  to more rapidly service a site in stage  226 . In a further embodiment, the locating operation may be further enhanced by providing an operator-controlled communication range adjustment feature for interrogator  30  (not shown) to assist in refining the location of a given device. Nonetheless, in other embodiments, devices  110  may be checked by a wireless communication technique that does not include the transmission of identification signals or a coordinating map. Further, in alternative embodiments, localization of devices  110  with interrogator  30  may not be desired. 
     Process  220  next encounters conditional  228 . Conditional  228  tests whether any of the status signals, corresponding to a broken pathway  154 , indicate termite activity. If the test of conditional  228  is negative, then monitoring loop  230  returns to stage  226  to again monitor devices  110  with interrogator  30 . Loop  230  may be repeated a number of times in this fashion. Typically, the rate of repetition of loop  230  is on the order of a few days or weeks and may vary. If the test of conditional  228  is affirmative, then process  220  continues with stage  240 . In stage  240 , the pest control service provider places a pesticide laden bait in the vicinity of the detected pests. In one example, pesticide placement includes the removal of cap  180  by the service provider and extraction of pest activity monitoring assembly  130  from housing  170 . Next, for this example, pest control device  110  is reconfigured, exchanging pest monitoring assembly  112  with pesticide delivery assembly  119  as previously described in connection with  FIG. 7 . 
     In other embodiments, the replacement device may include a different configuration of communication circuit or lack a communication circuit entirely. In one alternative, the pesticide is added to the existing pest sensing device by replacing one or more of the bait members  132 , and optionally, sensor  150 . In still another embodiment, pesticide bait or other material is added with or without the removal of pest monitoring assembly  112 . In yet a further embodiment, pesticide is provided in a different device that is installed adjacent to the installed device  110  with pest activity. During the pesticide placement operation of stage  240 , it is desirable to return or maintain as many of the termites as possible in the vicinity of the device  110  where the pest activity was detected so that the established pathway to the nest may serve as a ready avenue to deliver the pesticide to the other colony members. 
     After stage  240 , monitoring loop  250  is encountered with stage  242 . In stage  242 , devices  110  continue to be periodically checked. In one embodiment, the inspection of devices  110  corresponding to pesticide bait is performed visually by the pest control service provider while the inspection of other devices  110  in the monitoring mode ordinarily continues to be performed with interrogator  30 . In other embodiments, visual inspection may be supplemented or replaced by electronic monitoring using the pest activity monitoring assembly  130  configured with a poisoned bait matrix, or a combination of approaches may be performed. In one alternative, pathway  154  is altered to monitor pesticide baits such that it is typically not broken to provide an open circuit reading until a more substantial amount of bait consumption has taken place relative to the pathway configuration for the monitoring mode. In still other alternatives, the pesticide bait may not ordinarily be inspected—instead being left alone to reduce the risk of disturbing the termites as they consume the pesticide. 
     After stage  242 , conditional  244  is encountered that tests whether process  220  should continue. If the test of conditional  244  is affirmative—that is process  220  is to continue—then conditional  246  is encountered. In conditional  246 , it is determined if more pesticide bait needs to be installed. More bait may be needed to replenish consumed bait for devices where pest activity has already been detected, or pesticide bait may need to be installed in correspondence with newly discovered pest activity for devices  110  that remained in the monitoring mode. If the conditional  246  test is affirmative, then loop  252  returns to stage  240  to install additional pesticide bait. If no additional bait is needed as determined via conditional  246 , then loop  250  returns to repeat stage  242 . Loops  250 ,  252  are repeated in this manner unless the test for conditional  244  is negative. The repetition rate of loops  250 ,  252  and correspondingly the interval between consecutive performances of stage  242 , is on the order of a few days or weeks and may vary. If the test of conditional  244  is negative, then devices  110  are located and removed in stage  260  and process  220  terminates. 
     Data collected with interrogator  30  during performance of process  220  can be downloaded into unit  40  from time to time. However, in other embodiments, unit  40  may be optional or absent. In still another alternate process, monitoring for additional pest activity in stage  242  may not be desirable. Instead, the monitoring units may be removed. In a further alternative, one or more devices  110  configured for monitoring may be redistributed, increased in number, or decreased in number as part of the performance of the process. In yet other embodiments, a data collection unit is utilized to interface with one or more pest control devices in lieu of interrogator  30 . Additionally or alternatively, interfacing with interrogator  30  and/or unit  40  may be through a hardwired communication connection. 
       FIG. 11  illustrates pest control system  300  of another embodiment of the present invention where like reference numerals refer to like features previously described. Pest control system  300  includes pest control device  310  and data collection unit  390 . Pest control device  310  includes circuitry  320  removably coupled to sensor  350  by connection members  140 . 
     Referring additionally to the partial assembly view of  FIG. 12 , sensor  350  includes substrate  351  that carries electrically resistive network  353 . Network  353  includes a number of sensing elements  353   a  in the form of electrically resistive branches or pathways  354  spaced apart from one another along substrate  351 . Resistive pathways  354  are each schematically represented by a different resistor R 1 -R 13  in  FIG. 11 . Network  353  extends from contact pads  356  at edge  355  to substrate end portion  357 . When coupled together, network  353  and circuitry  320  comprise monitoring circuit  369 . 
     With further reference to the end view of  FIG. 13 , a fully assembled and implemented form of sensor  350  is shown. Sensor  350  is configured to be rolled, folded, bent, or wrapped about assembly axis A 1  as shown in  FIG. 13  to provide a number of adjacent layers  360 , only a few of which are designated by reference numerals. It should be understood that axis A 1  in  FIG. 13  is perpendicular to the  FIG. 13  view plane and is correspondingly represented by like-labeled cross-hairs. Referring back to  FIGS. 11 and 12 , circuitry  320  is contained in circuit enclosure  318 . Enclosure  318  can be configured in a manner like enclosure  118  of pest monitoring subassembly  114  for pest control device  110 . Indeed, enclosure  318  is arranged to receive a pair of connection members  140  to electrically couple pads  356  of sensor  350  to circuitry  320  in the same manner that pads  156  of sensor  150  are coupled to circuitry  160 . Circuitry  320  includes a reference resistor R R  connected in series with network  353  when circuitry  320  and sensor  350  are coupled together to form monitoring circuit  369 . A voltage reference V R  is also coupled across network  353  and reference resistor R R . The voltage across reference resistor R R , designated V i , is selectively digitized by Analog-to-Digital (A/D) converter  324  using standard techniques. The digital output from A/D converter  324  is provided to processor  326 . Processor  326  is operatively coupled to communication circuit  328 . 
     Processor  326  can be comprised of one or more components. In one example, processor  326  is a programmable digital microprocessor arrangement that executes instructions stored in an associated memory (not shown). In other examples, processor  326  can be defined by analog computing circuits, hardwired state machine logic, or other device types as an alternative or an addition to programmable digital circuitry. Memory is also preferably included in communication circuitry  320  to store digitized values determined with A/D converter  324  (not shown). This memory can be integral to A/D converter  324  or processor  326 , separate from either, or a combination of these. 
     Communication circuit  328  is of a wireless type, such as the active and passive wireless communication circuit embodiments previously described in connection with system  20 . Communication circuit  328  is arranged to communicate with processor  326 . Alternatively or additionally, communication circuit  328  can include one or more input/output (I/O) ports for hardwired communication. 
     One or more of voltage reference V R , A/D converter  324 , processor  326  or communication circuit  328  can be combined in an integrated circuit chip or unit. Further, circuitry  320 , and correspondingly monitoring circuit  369 , can be of a passive type powered by an external source; active with its own power source; or a combination of these. 
     Data collection unit  390  includes an active wireless transmitter/receiver (TXR/RXR)  392  configured to communicate with communication circuit  328  of device  310 , processor  394  coupled to TXR/RXR  392 , interface  396 , and memory  398 . Processor  394  and memory  398  can be the same as processor  42  and memory  44  of data collection unit  40 , respectively, or be of a different arrangement as would occur to those skilled in the art. Interface  396  provides for the option of a hardwired interface to device  310  and/or other computing devices (not shown). Data collection unit  390  is configured to receive and process information from one or more pest control devices as will be more fully described hereinafter. 
     Referring generally to  FIGS. 11-13 , it should be understood that network  353  can be represented by an equivalent resistance R S ; where R S  is a function of R 1 -R 13  (R S =f(R 1 -R 13 )). When R 1 -R 13  are known, R S  can be determined by applying standard electrical circuit analysis techniques for series and parallel resistances. Furthermore, it should be understood that R R  and R S  can be modeled as a voltage divider with respect to the reference voltage V R  such that the input voltage V i  to A/D converter  324  can be expressed by the following equation: V i =V R *(R R /(R R +R S )). 
     Substrate  351  and/or network  353  are provided from one or more materials that are subject to consumption or displacement by one or more pests of interest. As sensor  350  is consumed or displaced by such pests, resistive pathways  354  comprising branches of network  353  are disrupted, becoming electrically open. As one or more resistive pathways  354  become open, the value of R S  changes. Accordingly, with the proper selection of resistance values for resistive pathways  354  relative to each other, R R , and V R ; a number of different values of R S  can be provided in correspondence with the opening of different resistive pathways  354  and/or different combinations of open pathways  354 . 
     Unlike  FIG. 12 ,  FIG. 13  depicts sensor  350  after one or more pests have begun consumption or displacement of substrate  351  and/or network  353 . In  FIG. 13 , pest T is illustrated in connection with pest-created opening  370  that was caused by pest consumption or displacement. The location of pest-created opening  370  relative to network  353  corresponds to phantom overlay  380  shown in  FIG. 12 . Pest-created opening  370  partially penetrates several layers  360  of sensor  350  from outer sensor margin  372  towards the middle of sensor  350  in the vicinity of axis A 1 . The pest-created opening  370  corresponds to separation or displacement of one or more portions of sensor  350  relative to another portion that could result in opening one or more of resistive pathways  354 , depending on relative location. Such separation or displacement can result from the removal of one or more pieces from sensor  350  due to pest activity. Even if a piece of sensor  350  is not removed by pests, separation or displacement of sensor  350  can still occur due to pest activity that separates or displaces a first portion relative to a second portion in one sensor region, but leaves the first and second portions connected together in another sensor region. For example, in  FIG. 13  sensor portion  374  is separated or displaced relative to sensor portion  376  by the formation of opening  370 ; however, sensor portions  374  and  376  remain connected by sensor portion  378 . 
     It should be further understood that by spatially arranging the resistive pathways  354  in a predetermined manner, sensor  350  can be configured to generally indicate a progressively greater degree of consumption and displacement as the value of R S , and accordingly V i , change. For instance, the arrangement of substrate  351  shown in  FIG. 13  can be used to place resistive pathways  354  closer to substrate end portion  357  near the outer sensor margin  372 , such as those resistive pathways  354  corresponding to R 8  and R 9 . Because these resistive pathways  354  are closer to the outer margin  372 , they are more likely to be encountered by pests before other of the resistive pathways  354 . In contrast, resistive pathways  354  nearer to the middle of the rolled substrate  351  (axis A 1 ), such as those corresponding to R 1 , R 5  and R 10 , are most likely to be encountered last by the pests as they consume and displace sensor  350 . Thus, as R S  changes with the progressive consumption and displacement of pests from the outer sensor margin  372  towards the middle, the corresponding input voltage V i  can be used to represent a number of different nonzero degrees of consumption or displacement of sensor  350 . 
     Processor  326  can be used to evaluate one or more values corresponding to V i  digitized with A/D converter  324  to determine if a change in pest consumption or displacement has occurred. This analysis could include various statistical techniques to reduce the adverse impact of noise or other anomalies. Furthermore, the analysis could be used to determine the rate of consumption or displacement as well as any changes in that rate with respect to time. These results can be provided by processor  326  via communication circuit  328  based on certain predefined triggering thresholds, on a periodic basis, in response to an external query with data unit  390 , or through a different arrangement as would occur to those skilled in the art. 
     It should be understood that like pest control devices  110  of system  20 , several devices  310  can be used in a spaced apart relationship in a multiple device pest control system. Devices  310  can be arranged for placement in-ground, on-ground, or above-ground. Furthermore, devices  310  can be used with an interrogator to assist in locating them as described in connection with system  20 . Also, it should be understood that a number of different resistive network arrangements could be utilized at the same time in device  310  to facilitate the detection of differing degrees of pest consumption or displacement. In another alternative embodiment, a multilayer configuration is provided by stacking together a number of separate layers and electrically interconnecting the layers as required to provide a desired sensing network. In yet another alternative, sensor  350  is utilized in an unrolled, single layer configuration rather than being arranged as shown in  FIG. 13 . Still other embodiments include a different resistive sensing network configurations as would occur to those skilled in the art. 
     Referring to  FIGS. 14-16 , a further pest control system embodiment  400  utilizing a resistive network to determine different degrees of pest activity is illustrated; where like reference numerals refer to like features as previously described. System  400  includes data collection unit  390  as described in connection with system  300  and pest control device  410 . Pest control device  410  includes circuitry  420  coupled to sensor  450 . Circuitry  420  includes reference resistor R R , voltage reference V R , A/D converter  324 , and communication circuit  328  as previously described. Circuitry  420  also includes processor  426  that can be physically the same arrangement as processor  326 , but is configured to accommodate any processing differences between sensors  350  and  450  as further explained hereinafter. 
     Sensor  450  includes substrate  451  with surface  451   a  opposite surface  451   b . Substrate  451  defines a number of regularly spaced passages  456  from surface  451   a  to surface  451   b . Resistive network  453  is comprised of a number of sensing elements  453   a  in the form of electrically resistive members  455 . Each resistive member  455  extends through a different passage  456 . Resistive members  455  are electrically coupled in parallel to one another by electrically conductive layers  454   a  and  454   b  that are in contact with substrate surfaces  451   a  and  451   b , respectively. For this configuration, substrate  451  is comprised of an electrically insulative material relative to resistive members  455  and conductive layers  454   a  and  454   b.    
     Collectively, circuitry  420  and network  453  comprise monitoring circuit  469 . Referring specifically to  FIG. 14 , the parallel resistive members  455  of network  453  are each schematically represented by one of resistors RP 1 , RP 2 , RP 3 , . . . RPN- 2 , RPN- 1 , and RPN; where “N” is the total number of resistive members  455 . Accordingly, the equivalent resistance R N  of network  453  can be determined from the parallel resistance law: R N =(1/RP 1 +1/RP 2  . . . +1/RPN) −1 . The equivalent resistance R N  of network  453  forms a voltage divider with reference resistor R R  relative to reference voltage V R . The voltage across reference resistor R R , V i , is input to A/D converter  324 . 
     Substrate  451 , layers  454   a  and  454   b , and/or members  455  are provided from a material that is consumed or displaced by pests of interest. Further, sensor  450  is arranged so that pest consumption or displacement results in opening the electrical connections of the resistive members  455  to network  453  through separation or displacement of one or more portions of sensor  450  relative to other portions of sensor  450  as explained in connection with  FIG. 13 .  FIG. 16  depicts region  470  where material has been separated or displaced from sensor  450 , resulting in open electrical connections. In  FIG. 16 , the phantom outline  472  indicates the form factor of sensor  450  prior to pest activity. As more resistive members  455  are electrically opened, the equivalent resistance R N  of network  453  increases, causing a corresponding change in V i  that is monitored with circuitry  420  to determine different relative levels of pest consumption or displacement activity. 
     In one embodiment, resistive members  455  each generally have the same resistance, such that: RP 1 =RP 2 = . . . =RPN within expected tolerances. In other embodiments, the resistive members  455  can have substantially different resistances relative to one another. Processor  426  is configured to analyze changes in consumption and displacement as indicated by variation in V i  and transmit corresponding data to data collection unit  390  as discussed in connection with system  300 . Conductive layers  454   a  and  454   b  can be coupled to circuitry  420  using an elastomeric connector adapted to engage these surfaces or another arrangement as would occur to those skilled in the art. 
     Besides resistance, other electrical characteristics of a sensing element that change with pest consumption or displacement can be monitored to gather pest activity data. Referring to  FIGS. 17-19 , pest control system  500  of another embodiment of the present invention is illustrated; where like reference numerals refer to like features previously described. Pest control system  500  includes data collection unit  390  and pest control device  510 . Pest control device  510  is comprised of circuitry  520  and sensor  550 . 
     Referring specifically to  FIG. 17 , circuitry  520  includes voltage reference V R , A/D converter  324 , and communication circuit  328  as previously described. Circuitry  520  also includes processor  526  coupled between A/D converter  324  and communication circuit  328 . Processor  526  can be of the same physical type as processor  326  of system  300 , but is configured to accommodate aspects of system  500  that differ from system  300 . For example, processor  526  is operably coupled to a number of switches  530   a ,  530   b , and  530   c  by signal control pathways  531   a ,  531   b  and  531   c , respectively. Processor  526  is arranged to selectively open and close switches  530   a - 530   c  by sending corresponding signals along the respective pathways  531   a - 531   c . Switches  530   a - 530   c  are each schematically illustrated as being of the single-pole, single-throw operational configuration. Switches  530   a - 530   c  can be of a semiconductor type, such as an Insulated Gate Field Effect Transistor (IGFET) arrangement, an electromechanical variety, a combination of these, or such other types as would occur to those skilled in the art. 
     Circuitry  520  also includes reference capacitor C R  that is coupled in parallel to switch  530   c , and voltage amplifier (AMP.)  523 . Voltage amplifier  523  amplifies input voltage V Q  and provides an amplified output voltage V 0  to A/D converter  324  to be selectively digitized. 
     In  FIG. 17 , sensor  550  includes sensing element  553   a  that is schematically depicted in the form of a capacitor with electrode  554 . Collectively, circuitry  520  and sensor  550  define monitoring circuit  569 . Within monitoring circuit  569 , voltage reference V R , switches  530   a - 530   c , reference capacitor C R , and sensor  550  provide sensing network  553 . In sensing network  553 , voltage reference V R  forms a branch that is electrically coupled to ground and one terminal of switch  530   a . The other terminal of switch  530   a  is electrically coupled to electrode  554  and a terminal of switch  530   b . The other terminal of switch  530   b  is coupled to the input of voltage amplifier  523 , to reference capacitor C R , and to a terminal of switch  530   c  by a common electrical node. Switch  530   c  is coupled in parallel to reference capacitor C R , both of which also have a terminal that is grounded. 
     Referring also to  FIGS. 18-19 , sensor  550  has end portion  555  opposite end portion  557 , and is comprised of multiple layers  560  including dielectric  551  and electrode- 554 . Dielectric  551  defines surface  551   a  opposite surface  551   b . Electrode  554  includes surface  554   a  in contact with surface  551   a . As depicted, surfaces  551   a  and  554   a  are generally coextensive. 
     Sensor  550  is depicted in  FIG. 17  as a capacitor in an “open electrode” configuration; where the electrical connection to ground is by way of dielectric  551 , and possibly other substances such as an air gap between dielectric  551  and the ground. In other words, sensor  550  does not include a predefined pathway to ground—instead allowing for the possibility that the ground coupling will vary. This dielectric coupling is symbolized by a dashed line representation  556  for sensor  550  in  FIG. 17 . 
     Dielectric  551  and/or electrode  554  is comprised of one or more materials consumed or displaced by a pest of interest. As pests consume or displace these materials, one portion of dielectric  551  and/or electrode  554  is removed or separated relative to another.  FIG. 19  illustrates region  570  that has been consumed or displaced by pests. Region  570  corresponds to the phantom overlay  580  shown in  FIG. 18 . This type of mechanical alteration of sensor  550  tends to change the ability of electrode  554  to hold charge Q and correspondingly changes capacitance C S  of sensor  550 . For example, as the area of electrode surface  554   a  decreases, the relative charge-holding capacity or capacitance of electrode  554  decreases. In another example, as the dielectric dimensions are altered or the dielectric composition changes, capacitance typically varies. In a further example, a change in distance between electrode  554  and the ground as caused by separation or displacement of one or more portions of sensor  550  can impact the ability to hold charge. 
     Referring generally to  FIGS. 17-19 , one mode of operating circuitry  520  is next described. For each measurement taken with this mode, a switching sequence is executed by processor  526  as follows: (1) switch  530   a  is closed while holding switch  530   b  open to place voltage reference V R  across sensor  550 , causing a charge Q to build on electrode  554 ; (2) after this charging period, switch  530   a  is opened; (3) switch  530   b  is then closed to transfer at least a portion of charge Q to reference capacitor C R  as switch  530   c  is held open; and (4) after this transfer, switch  530   b  is reopened. The voltage V Q  corresponding to the charge TQ transferred to reference capacitor C R  is amplified with amplifier  523  and presented as an input voltage to A/D converter  324 . The digitized input to A/D converter  324  is provided to processor  526  and/or stored in memory (not shown). After the voltage is measured, reference capacitor C R  can be reset by closing and opening switch  530   c  with processor  526 . The sequence is then complete. For a sensor capacitance C S  that is much smaller than the reference capacitance C R  (C S &lt;&lt;C R ), capacitance C S  can be modeled by the equation: C S =C R *(V Q /V R ) for this arrangement. 
     Processor  526  can be arranged to repeat this switching sequence from time to time to monitor for changes in Q and correspondingly C S . This data can be analyzed with processor  526  and reported through communication circuit  328  using the techniques described in connection with system  300 . These repetitions can be periodic or nonperiodic; by demand through another device such as communication circuit  328 ; or through different means as would occur to those skilled in the art. 
     In an alternative embodiment, a burst mode of charge/capacitance monitoring can be used. For the burst mode, processor  526  is configured to repeat the sequence of: (1) closing switch  530   a  while switch  530   b  is held open to charge electrode  554  and isolate reference capacitor C R , (2) opening switch  530   a , and then (3) closing switch  530   b  to transfer charge to reference capacitor C R . Switch  530   c  remains open throughout these repetitions for this mode. As a result, reference capacitor C R  is not reset as the repetitions are executed. Once a desired number of the repetitions are completed (a “burst”), A/D converter  324  digitizes the input voltage. By executing the repetitions rapidly enough, the amount of charge Q transferred from electrode  554  to reference capacitor C R  increases. This increased charge transfer provides a relative increase in gain. Accordingly, gain can be controlled by the number of repetitions executed per burst. Also, reference capacitor C R  operates as an integrator to provide a degree of signal averaging. 
     In other alternative embodiments, network  560  can be operated to continuously repeat the burst mode sequence with a resistor in place of switch  530   c  to facilitate concurrent monitoring. For this arrangement the resistor used for switch  530   c  and reference capacitor C R  define a single pole, low pass filter. This continuous mode has a “charge gain” (expressed in electric potential per unit capacitance) determined as a function of the replacing resistor, the reference voltage V R , and the frequency at which the repetitions are performed. In still other alternatives, network  560  is modified to use an operational amplifier (opamp) integrator or unipolar equivalent as described in  Charge Transfer Sensing  by Hal Phillip (dated 1997), which is hereby incorporated by reference. In still other embodiments, a different circuit arrangement to measure charge Q, voltage V 0 , C S , or another value corresponding to C S  can be used as would occur to those skilled in the art. 
     Electrode  554  can be electrically connected to circuitry  520  with an elastomeric connector or a different type of connector as would occur to those skilled in the art. In an alternative embodiment, sensor  550  can be arranged to include a defined pathway to ground rather than an open electrode configuration, or a combination of both approaches. Still other embodiments include a stacked, wrapped, folded, bent, or rolled arrangement of alternating electrode layers and dielectric layers with one or more of the layers being of a material consumed or displaced by pests of interest. Alternatively or additionally, a sensor can include two or more separate electrodes or sensing capacitors arranged in a network in series, in parallel, or a combination of these. 
     In other embodiments, electrode  554  of sensor  550  can be applied to sense one or more properties besides pest consumption or displacement. In one example, sensor  550  is arranged to detect wear, abrasion, or erosion. For this arrangement, sensor  550  is formed from one or more materials disposed to wear away in response to a particular mechanical activity that correspondingly changes the charge holding capacity of electrode  554 . For example, the area of surface  554   a  of electrode  554  could be reduced as one or more portions are removed due to this activity. Circuitry  520  can be used to monitor this change and report when it exceeds a threshold value indicative of a need to replace or service a device being monitored with the sensor, discontinue use of such device, or take another action as would occur to those skilled in the art. 
     In another example, sensor  550  is formed from one or more materials selected to separate or otherwise decrease charge holding capacity in response to a change in an environmental condition to which the one or more materials are exposed, a chemical reaction with the one or more materials, or through a different mechanism as would occur to those skilled in the art. For these nonpest embodiments, operation of processor  526  can correspondingly differ. Also, a hardwired connection, an indicator, and/or other device may be utilized as an addition or alternative to communication circuit  328 . 
     Referring to systems  300 ,  400 , and  500  generally, one or more conductive elements, resistive elements, or capacitive elements of sensors  350 ,  450 ,  550  can be comprised of a carbon-containing ink as described in connection with pest control device  110 . Indeed, different resistance values for various sensing elements, such as elements  353   a  and  453   a , can be defined by using inks with different volume resistivities. Alternatively or additionally, different resistance values can be defined by varying dimensions of the material through which electricity is conducted and/or employing different interconnected components for these elements. Furthermore, substrates  351 ,  451 , and/or  551  can be formed from a paper coated with a polymeric compound, such as polyethylene, to reduce dimensional changes due to moisture as described in connection with pest control device  110 . 
       FIG. 20  illustrates a fifth type of pest control system  620  that includes pest control devices  310 ,  410 ,  510 , and  610 , where like reference numerals refer to like features previously described. System  620  includes building  622  that houses data collection unit  390 . System  620  also includes a central data collection site  626  that is connected by communication pathway  624  to data collection unit  390 . Communication pathway  624  can be a hardwired connection through a computer network such as the internet, a dedicated telephone interconnection, a wireless link, a combination of these, or such other variety as would occur to those skilled in the art. 
     For system  620 , pest control devices  310  are depicted in-ground for use as discussed in connection with system  20 . Pest control devices  410  and  510  of system  620  are located within building  622 , and are shown at or above ground level. Pest control devices  310 ,  410 ,  510  are arranged to communicate with data collection unit  390  through wireless means, hardwired means, through another device like a hand-held interrogator  30 , or a combination of these. 
     Pest control device  610  is comprised of circuitry  420  previously described and sensor  650 . Sensor  650  includes network  453  comprised of sensing elements  453   a . For sensor  650 , network  453  is directly coupled to member  628  of building  622 . Member  628  is comprised of one or more materials subject to destruction by one or more species of pests. For example, member  628  can be formed of wood when termites are the targeted type of pest. As a result, pest activity relative to member  628  of building  622  is directly monitored with pest control device  610 . Like pest control devices  310 ,  410 , and  510 , pest control device  610  communicates with data collection unit  390  through wireless means, hardwired means, through another device like a hand-held interrogator  30 , or a combination of these. 
     Central data collection site  626  can be connected to a number of data collection units  390  arranged to monitor different buildings or areas each having one or more of pest control devices  110 ,  310 ,  410 ,  510 , and/or  610 . 
       FIG. 21  illustrates pest control device system  720  of still another embodiment of the present invention; where like reference numerals refer to like features previously described. System  720  includes interrogator  730  and pest control device  710 . Pest control device  710  includes pest monitoring member  732  arranged to be consumed and/or displaced by pests. In one example, member  732  is configured as a bait that includes pest-edible material  734 , such as wood in the case of termites, and magnetic material  736  in the form of a coating on material  734 . Magnetic material  736  may be a magnetic ink or paint applied to a wood core serving as material  734 . In other examples, material  734  may be formed from a substance other than a food source that is typically removed or displaced by the targeted pests—such as a closed cell foam in the case of subterranean termites. In yet other examples, material  734  may be comprised of food and non-food components. 
     Device  710  further includes wireless communication circuit  780  electrically coupled to magnetic signature sensor  790 . Sensor  790  comprises a series of magnetoresistors  794  fixed in a predetermined orientation relative to member  732  to detect a change in resistance resulting from an alteration in the magnetic field produced by magnetic material  736 . Accordingly, material  736  and magnetoresistors  794  are alternatively designated sensing elements  753   a . Alterations in the monitored magnetic field can occur, for instance, as member  732  is consumed, displaced, or otherwise removed from member  732  by pests. Sensor  790  provides a means to characterize a magnetic signature of member  732 . In alternative embodiments, sensor  790  may be based on a single magnetoresistor, or an alternative type of magnetic field sensing device such as a Hall effect device or reluctance-based sensing unit. 
     The magnetic field information from sensor  790  may be transmitted as variable data with communication circuit  780 . Circuit  780  may further transmit a unique device identifier and/or discrete bait status information as described for communication circuit  160 . Circuit  780 , sensor  790 , or both may be passive or active in nature. 
     Interrogator  730  includes communication circuit  735  operable to perform wireless communication with circuit  780  of device  710 . In one embodiment, circuits  780  and  790  are of a passive type with circuit  780  being in the form of an RF tag like circuitry  160 . For this embodiment, communication circuit  735  is configured comparable to circuits  32  and  34  of interrogator  30  to perform wireless communications with device  710 . In other embodiments, device  710  may be adapted to alternatively or additionally include an active wireless communication circuit and/or hardwired communication interface. For these alternatives, interrogator  730  is correspondingly adapted, a data collection unit may be used in lieu of interrogator  730 , or a combination of both approaches may be utilized. 
     Interrogator  730  includes controller  731 , I/O port  737 , and memory  738  that are the same as controller  36 , I/O port  37 , and memory  38  of interrogator  30 , except they are configured to receive, manipulate and store magnetic signature information in addition or as an alternative to discrete bait status and identification information. It should be appreciated that like the resistance characteristics of devices  310 ,  410 , and  610  or the capacitance characteristics of device  510 ; magnetic signature information may be evaluated to characterize pest consumption behavior. This behavior may be used to establish predictions concerning bait replenishment needs and pest feeding patterns. 
       FIG. 22  depicts system  820  of still another embodiment of the present invention. System  820  includes pest control device  810  and data collector  830 . Device  810  includes monitoring member  832  arranged to be consumed and/or displaced by the pests of interest. Member  832  includes matrix  834  with a magnetic material  836  dispersed throughout. Material  836  is schematically represented as a number of particles in matrix  834 . Matrix  834  may have a food composition, non-food composition, or a combination of these. 
     Device  810  also includes communication circuit  880  and sensor circuit  890  electrically coupled thereto. Circuit  890  includes a series of magnetoresistors  894  fixed in relation to member  832  to detect change in a magnetic field produced by material  836  as it is consumed, displaced, or otherwise removed from member  832 . 
     Circuit  890  further includes a number of environmental (ENV.) sensors  894   a ,  894   b ,  894   c  configured to detect temperature, humidity, and barometric pressure, respectively. Material  836  and sensor  894 ,  894   a ,  894   b , and  894   c  are alternatively designated sensing elements  853   a . Sensors  894 ,  894   a ,  894   b ,  894   c  are coupled to substrate  838 , and may provide a signal in either a digital or analog format compatible with associated equipment. Correspondingly, circuit  890  is configured to condition and format signals from sensors  894   a ,  894   b ,  894   c . Also, circuit  890  conditions and formats signals corresponding to the magnetic signature detected with magnetoresistors  894 . The sensed information provided by circuit  890  is transmitted by communication circuit  880  to data collector  830 . Communication circuit  880  may include discrete bait status information, a device identifier, or both as described in connection with devices  110 . Circuit  880  and circuit  890  may each be passive, active, or a combination of both with data collector  830  being correspondingly adapted to communicate in accordance with the selected approach. 
     For a passive embodiment of circuit  880  based on RF tag technology, data collector  830  is configured the same as interrogator  30  with the exception that its controller is arranged to manipulate and store the different forms of sensed information provided by circuit  890 . In another embodiment, data collector  830  may be in the form of a standard active transmitter/receiver to communicate with an active transmitter/receiver form of circuit  880 . In still other embodiments, data collector  830  and device  810  are coupled by a hardwired interface to facilitate data exchange. 
       FIGS. 23 and 24  depict pest control device  1010  of a further embodiment of the present invention; where like reference numerals refer to like features. Pest control device  1010  includes communication circuitry  1020 , connector  1040 , and sensor  1050  configured in a pest monitoring arrangement  1060  as shown in  FIG. 23 . Communication circuitry  1020  includes activation device  1022  and indicating device  1024  to output information. Communication circuitry  1020  also includes other components assembled to provide circuit subassembly module  1044 . Module  1044  can include a printed wiring board to electrically interconnect various components and/or other members to mechanically support communication circuitry  1020 . Module  1044 , and correspondingly communication circuitry  1020 , are electrically and mechanically coupled to sensor  1050  by connector  1040 . Connector  1040  can include an electrically conductive elastomeric material as described for connection members  140  of pest control device  110 , and/or such different materials or configuration as would occur to one skilled in the art. 
     Sensor  1050  includes substrate  1051  carrying pest sensing circuit  1052 . Pest sensing circuit  1052  includes an electrically conductive loop or network that has an electrical resistance below a predefined level when installed and that is subject to alteration by pest activity as previously described for conductor  153  of pest control device  110 . Substrate  1051  and/or pest sensing circuit  1052  include material that is typically displaced or consumed by one or more pests to be monitored with arrangement  1060 . When coupled to communication circuitry  1020 , pest sensing circuit  1052  cooperates therewith to provide monitoring circuitry  1069 . 
     Pest monitoring arrangement  1060  further includes bait  1032 , a surface of which is shown by the cut away view in the lower portion of  FIG. 23 . Bait  1032  can be configured the same as bait member  132  or any previously described variations thereof. In one arrangement, bait  1032  is in the form of at least two members positioned on opposing sides of sensor  1050  as depicted in  FIGS. 3 and 6  for bait members  132  in relation to sensor  150  of pest control device  110 . 
     Pest monitoring arrangement  1060  is configured as a portable unit for installation in and removal from housing  1070 . Housing  1070  can be shaped and composed of material suitable for installation in the ground like housing  170  described in connection with pest control device  110 . Sensor  1050  is fixed in relation to circuit subassembly module  1044  by connector  1040  which is in turn fixed to cap  1080  (shown in section). Carrying member  1090  provides further mechanical support for arrangement  1060 , including one or more side members (not shown) connected to module  1044  and/or cap  1080 . Cap  1080  can be configured comparably to cap  180  of pest control device  110 , allowing for the mounting of devices  1022  and  1024  as illustrated. Carrying member  1090  can be configured comparably to carrying member  190  of pest control device  110 , and may be permanently fixed in relation to module  1044  and/or cap  1080 , or selectively connected thereto. 
     In  FIG. 24 , communication circuitry  1020  is shown in a schematic form. Activation device  1022  is further shown in the form of a “normally open” push button switch  1022   a , such that electrical contact is made only as long as switch  1022   a  is being pressed in the direction indicated by arrow  1023 . Indicating device  1024  is shown in the form of a Light Emitting Diode (LED)  1024   a  that can be selectively illuminated to output information. Components of communication circuitry  1020  also include electrical energy source  1025  arranged to supply a generally constant voltage V, resistor  1026 , and NPN transistor  1027  electrically interconnected as shown in  FIG. 24 . 
     Referring generally to  FIGS. 23 and 24 , the operation of pest control device  1010  is next described. Pest control device  1010  is arranged for placement in a region to be monitored for one or more pests as illustrated for various pest control devices in  FIG. 2  and  FIG. 20 . Further, as depicted, pest control device  1010  is suitable for installation in the ground. Indeed, during normal use, one or more pest control devices  1010  are installed at least partially below ground with cap  1080  remaining accessible. 
     Once installed, an operator stimulates operation of communication circuitry  1020  (and correspondingly monitoring circuitry  1069 ) by pressing switch  1022   a . In response, emitter  1027   e  of transistor  1027  is grounded relative to voltage supplied by source  1025 . With emitter  1027   e  grounded, LED  1024   a  will emit light when transistor  1027  is active, such that voltage from source  1025  drops across LED  1024   a , and the collector  1027   c  and emitter  1027   e  terminals of transistor  1027 . Transistor  1027  is activated with switch  1022   a  being closed if an electrical interconnection between source  1025  and base  1027   b  of transistor  1027  presents a voltage level to base  1027   b  sufficient to turn-on transistor  1027 . This electrical interconnection includes the resistance of resistor  1026  and pest sensing circuit  1052  in series. Accordingly, for an electrical resistance of pest sensing circuit  1052  at or below a given threshold, LED  1024   a  is illuminated if switch  1022   a  is pressed. However, as pests consume or displace substrate  1051  and/or pest sensing circuit  1052 , resulting circuit alteration can cause a sufficiently increased electrical resistance or open circuit condition so that transistor  1027  is no longer activated by pressing switch  1022   a , and correspondingly LED  1024   a  will not emit light. 
     Through the operation of communication circuitry  1020 , a two-state signal is provided with LED  1024   a  that visually indicates whether or not the electrical continuity/resistance of pest sensing circuit  1052  has been altered. This two-state signal can be used to determine when to reconfigure pest control device  1010  to add a pesticide, exchange pest monitoring arrangement  1060  with a pesticide delivery arrangement, and/or prompt another action. Such other actions may include installing additional devices with or without pesticide. In still a further embodiment, pest control device  1010  is configured to initially include a pesticide laden bait so that communication circuitry  1020  provides information indicative of pesticide consumption. 
     For one embodiment of the present invention, resistor  1026  is nominally about 10,000 ohms, source  1025  provides a generally constant three volt output and is in the form of one or more electrochemical cells (e.g., a “battery”), transistor  1027  is of a standard bipolar junction switching variety, and pest sensing circuit  1052  is an electrically conductive loop as described in connection with pest control device  110 . In other embodiments, electrical energy source  1025 , the value of resistor  1026 , and/or nature of transistor  1027  can differ. Such alternative arrangements can include a PNP bipolar junction transistor, a Field Effect Transistor (FET), an electromechanical relay, or a Solid State Relay (SSR) in place of NPN transistor  1027  with corresponding adjustments to circuitry  1020 , to name only a few possibilities. Alternatively or additionally, source  1025  can be of a form other than a battery, can be external to device  1010  and/or can be selectively applied to device  1010  by an operator. 
     Alternatively or additionally, monitoring circuitry  1069  can be adapted to communicate different information about the device. For example, an additional subcircuit can be included to test whether the voltage source  1025  is operational. In another example, the manual interrogation of pest sensing circuit with activation device  1022  and output with device  1024  can be added to wireless communication circuits of previously described pest control devices to provide a manually triggered operational test. In still another example, the manual interrogation technique is utilized to output different nonzero levels of pest consumption or displacement. Accordingly, information quantitizing the amount of consumption or displacement can be realized in response to the manual stimulus. For such embodiments, the sensor arrangements of devices  310 ,  410 ,  510 ,  610 ,  710 , and/or  810  can be utilized with appropriate adaptations to communication circuitry  1020  to provide for activation by a switch or other operator input device. In one such form, multiple LEDs or another visual display arrangement output varying nonzero levels of consumption. In still another form, a single two-state indicating LED is utilized; however, a threshold level is set that corresponds to a given nonzero degree of consumption or displacement. This threshold can be factory set and/or set with an operator control. 
     In further embodiments, an activation device different than a normally open switch  1022   a  can be alternatively or additionally utilized. In one example, the activation device is in the form of a wireless RF receiving circuit. In another example, the activation device is in the form of a switch with more than two states or such different form as would occur to one skilled in the art. For other embodiments, an indicating device other than an LED can be used. Such an indicator can be visual, audible, a combination of these, or such different type as would occur to those skilled in the art. In one example, the identifying device is in the form of an incandescent lamp or electromechanical indicator. In another example, the indicating device is in the form of an RF signal transmitter that outputs information provided by monitoring circuitry  1069  in response to a stimulus with activation device  1022 . In still another form, activation device  1022 , indicating device  1024 , and/or other features of communication circuitry  1020  are provided in the form of a signal transponder that can be active or passive in nature. In yet another form, activation device  1022 , indicating device  1024 , and/or other features of communication circuitry  1020  are configured as a unit that can engage and disengage from the rest of device  1010  by way of a connector or otherwise. For this form, such a unit could be used to interrogate multiple devices  1010  by manually engaging/disengaging each of the multiple devices  1010  in a desired sequence. In a further variation, such a unit could be configured to retain the information from multiple devices  1010 . 
       FIG. 25  depicts pest control system  1100  of a further embodiment of the present invention, where like reference numerals refer to like features. Pest control system  1100  includes an operator-controlled magnetic activation device in the form of wand  1102 . Wand  1102  includes body  1104  with operator grip  1106  and magnetic field source  1108 . Magnetic field source  1108  provides magnetic field MF symbolically depicted in  FIG. 25 . Magnetic field source  1108  can be provided by a permanent magnet or an electromagnet, to name a few examples. 
     System  1100  also includes pest control device  1110 . Referring additionally to  FIG. 26 , pest control device  1110  includes communication circuitry  1120 , connector  1040 , and sensor  1150  configured in a pest monitoring arrangement  1160 . Communication circuitry  1120  includes device  1122  responsive to magnetic field MF when in close proximity thereto, and indicators  1136  and  1138  to output information. Communication circuitry  1120  also includes other components assembled to provide circuit subassembly module  1144 . Module  1144  can include a printed wiring board to electrically interconnect various components and/or other members to mechanically support communication circuitry  1120 . Module  1144 , and correspondingly communication circuitry  1120 , are electrically and mechanically coupled to sensor  1150  by connector  1040 , as previously described in connection with pest control device  1010 . 
     Sensor  1150  includes substrate  1051  carrying pest sensing circuit  1152 . Pest sensing circuit  1152  includes an electrically conductive loop or network that has an electrical resistance, represented in  FIG. 26  by R 1 , that is below a predefined level when installed and that is subject to alteration by pest activity as previously described for conductor  153  of pest control device  110 . Substrate  1051  and/or pest sensing circuit  1152  include material that is typically displaced or consumed by one or more pests to be monitored with arrangement  1160 . When coupled to communication circuitry  1120 , pest sensing circuit  1152  cooperates therewith to provide monitoring circuitry  1169 . Pest monitoring arrangement  1160  further includes bait  1032  as previously described in connection with device  1010 , a surface of which is shown by the cut away view in the lower portion of  FIG. 25 . 
     Pest monitoring arrangement  1160  is configured as a portable unit for installation in and removal from housing  1070 , as previously described for device  1010 . Sensor  1150  is fixed in relation to circuit subassembly module  1144  by connector  1040  which is in turn fixed to cap  1180  (shown in section). Also, as described for device  1010 , member  1090  provides further mechanical support for arrangement  1160 , including one or more side members (not shown) connected to module  1144  and/or cap  1180 . Cap  1180  can be configured comparably to cap  1080  of pest control device  1010 , allowing for the mounting of devices  1136  and  1138  as illustrated. 
     In  FIG. 26 , communication circuitry  1120  is shown in a schematic form. Activation device  1122  is further shown in the form of a “normally open” switch  1123 , such that switch  1123  is closed only as long as device  1122  is activated by magnetic field MF shown in  FIG. 25 . Indicators  1136  and  1138  are each provided in the form of LED  1124  that can be selectively illuminated with communication circuitry  1120 . Components of communication circuitry  1120  also include electrical energy source  1125  arranged to supply a generally constant voltage VS, resistors R 2 -R 4 , and comparators  1132  and  1134  electrically interconnected as shown in  FIG. 26 . 
     Referring generally to  FIGS. 25 and 26 , the operation of pest control device  1110  is next described. Pest control device  1110  is arranged for placement in a region to be monitored for one or more pests as illustrated for various pest control devices in  FIG. 2  and  FIG. 20 . Further, as depicted, pest control device  1110  is suitable for installation in the ground. Indeed, during normal use, one or more pest control devices  1110  are installed at least partially below ground, with cap  1180  remaining at least partly visible. 
     Once pest control device  1110  is installed, an operator stimulates operation of communication circuitry  1120  (and correspondingly monitoring circuitry  1169 ) by placing wand  1102  proximate to cap  1180  to align magnetic field MF with device  1122  in a manner sufficient to correspondingly actuate device  1122  so that switch  1123  closes. With switch  1123  being closed, energy source  1125  is electrically coupled to the other components of communication circuitry  1120  via electrical node  1126 . Resistors R 2  and R 3  are configured as a voltage divider that provides a reference voltage VREF to the inverting (−) input of comparator  1132  and to the noninverting (+) input of comparator  1134 , while switch  1123  couples the voltage VS of source  1125  to circuit node  1126 . Resistor R 4  and the resistance of pest sensing device  1152 , represented by R 1 , also form a voltage divider that is electrically parallel to the voltage divider formed by resistors R 2  and R 3 . A sense voltage, VSENSE, is applied to the noninverting (+) input of comparator  1132  and the inverting (−) input of comparator  1134 . Both the R 2 /R 3  and R 1 /R 4  voltage dividers are coupled between VS and electrical ground while switch  1123  is closed. 
     The relative resistance values of the four resistors, R 1 -R 4 , are selected so that VREF is nominally greater than VSENSE, prior to any alteration of pest sensing circuit  1152 . Letting the impedance of the inverting (−) and noninverting (+) inputs of comparators  1132  and  1134  be infinite (typically a reasonable approximation for values of R 1 -R 4  each less than one million ohms), then VREF=VS(R 3 /(R 2 +R 3 ) and VSENSE=VS(R 1 /R 1 +R 4 )). 
     When VREF is greater than VSENSE (VREF&gt;VSENSE), the output of comparator  1134  is at a high state and the output of comparator  1132  is at a low state. For these conditions, voltage VS is presented across LED  1124  of indicator  1136 , causing it to emit light if VS is sufficiently large enough. In contrast, a turn-on voltage is not provided to LED  1124  of indicator  1138 , preventing its illumination. 
     However, as pest activity increases, the resistance of pest sensing circuit  1152 , R 1 , increases. If R 1  exceeds R 3 , then VSENSE becomes greater than VREF (VSENSE&gt;VREF) and the output states of comparators  1132  and  1134  reverse. Correspondingly, indicator  1138  illuminates while indicator  1136  does not, which provides information showing a change in status of pest sensing circuit  1152  compared to conditions for VREF&gt;VSENSE. Anytime magnetic field MF is separated from device  1122  sufficiently by moving wand  1102  or otherwise, switch  1123  opens, removing VS from node  1126  and deactivating communication circuitry  1120 , such that neither indicator  1136  nor  1138  is illuminated. 
     Through the operation of communication circuitry  1120 , a two-state signal is provided with indicators  1136  and  1138  that each visually indicates whether or not the electrical continuity/resistance of pest sensing circuit  1152  has been altered relative to an established threshold. This two-state signal can be used to determine when to reconfigure pest control device  1110  to add a pesticide, exchange pest monitoring arrangement  1160  with a pesticide delivery arrangement, and/or prompt another action. Such other actions may include installing additional devices with or without pesticide. In still a further embodiment, pest control device  1110  is configured to initially include a pesticide laden bait so that communication circuitry  1120  provides information indicative of pesticide consumption. 
     For one embodiment of the present invention, resistors R 2  and R 4  are nominally 330,000 ohms, resistor R 3  is nominally about 25,000 ohms and the resistance of pest sensing circuit  1152  is nominally about 15,000 ohms (R 1 ) before alternation by pests. For this embodiment, source  1125  provides a generally constant three (3) volt output and is in the form of one or more electrochemical cells (e.g., a “battery”), comparator  1132  and  1134  are each of an LM339 variety, device  1122  is in the form of a magnetically activated reed switch, indicator  1136  is in the form of a green colored LED, and indicator  1138  is in the form of a red colored LED. In other embodiments, electrical energy source  1125 , the value of resistances represented by any of resistors R 1 -R 4 , device  1122 , indicators  1136  and  1138 , and/or comparators  1132  and  1134  can differ. In one alternative embodiment, VREF is provided by a voltage reference other than a voltage divider. For example, a zener diode, a bandgap reference, and/or a voltage regulator component could be used instead just to name a few. 
     Besides a magnetic reed switch form of device  1122 , other magnetically activated devices could be used, such as one or more Hall effect sensors, an electromechanically activated component, an inductive coil responsive to external magnetic fields, or such different device type as would occur to those skilled in the art. Alternatively or additionally, the activation is performed with a device that has more than two operational states. 
     In other embodiments, only a single indicator is used. For one form of this embodiment, an LED only illuminates when pest activity is detected or when pest activity is not detected, but not for both. For another form of this embodiment, a multicolor LED type of indicator is used instead of two discrete LED components. For other embodiments, one or more indicators other than an LED can be used. Such an indicator can be visual, audible, a combination of these, or such different type as would occur to those skilled in the art. In one example, the indicator is in the form of an incandescent lamp or electromechanical indicator. In another example, the indicator is in the form of an RF signal transmitter that outputs information provided by monitoring circuitry  1169  in response to a magnetic field MF stimulus. It should be understood that magnetic field MF can be the magnetic field component(s) of time varying electromagnetic radiation. 
     In still another form, device  1122 , indicator(s)  1136  and  1138 , and/or other features of communication circuitry  1120  are provided in the form of a signal transponder that can be active or passive in nature. In yet another form, device  1122 , source  1125 , indicator(s)  1136  and  1138  and/or other features of communication circuitry  1120  are configured as a unit that can engage and disengage from the rest of device  1110  by way of a connector or otherwise. For this form, such a unit could be used to interrogate multiple devices  1110  by manually engaging/disengaging each of the multiple devices  1110  in a desired sequence. In a further variation, such a unit could be configured to retain the information from multiple devices  1110 . 
     Further embodiments include circuitry and/or component(s) other than comparators to provide desired output states indicative of the status of pest sensing circuit  1152 . For example, one or more transistors, logic devices, and the like responsive to a change in the status of pest sensing circuit  1152  could be used. Alternatively or additionally, source  1125  can be of a form other than a battery, can be external to device  1110  and/or can be selectively applied to device  1110  by an operator. In one alternative, the magnetic field stimulus MF is of a varying type and communication circuit  1120  is configured to derive operating power from it in addition to or as an alternative to source  1125 . 
     Alternatively or additionally, monitoring circuitry  1169  can be adapted to communicate different information about the device. For example, an additional subcircuit can be included to test whether source  1125  is operational. In another example, the manual interrogation of pest sensing circuit with wand  1102  and corresponding output with indicators can be added to wireless communication circuits of previously described pest control devices to provide an operator triggered test. In still another example, the manual interrogation technique embodied in device  1110  is utilized to output different nonzero levels of pest consumption or displacement. Accordingly, information quantitizing the amount of consumption or displacement can be realized in response to the stimulus. For such embodiments, the sensor arrangements of devices  310 ,  410 ,  510 ,  610 ,  710 , and/or  810  can be utilized with appropriate adaptations to communication circuitry  1120  to provide for activation by a magnetically activated device or other operator input device. In one such form, multiple LEDs or another visual display outputs varying nonzero levels of consumption. In still another form, a single two-state indicating LED is utilized; however, a threshold level is set that corresponds to a given nonzero degree of consumption or displacement. This threshold can be factory set and/or set by an operator. 
       FIG. 27  depicts pest control system  1200  of a further embodiment of the present invention, where like reference numerals refer to like features. System  1200  also includes pest control device  1210 . Referring additionally to  FIG. 28 , pest control device  1210  includes circuitry  1220 , connector  1040 , and sensor  1250  configured in a pest monitoring arrangement  1260 . Circuitry  1220  includes indicator arrangement  1230 . Arrangement  1230  includes indicators  1136  and  1138  in the form of LEDs  1124  as previously described. Circuitry  1220  also includes one or more other components assembled to provide circuit subassembly module  1244 . Module  1244  can include a printed wiring board to provide various electrical interconnections, and/or other members to mechanically support circuitry  1220 . Module  1244 , and correspondingly circuitry  1220 , are electrically and mechanically coupled to sensor  1250  by connector  1040 , as previously described. 
     Sensor  1250  includes substrate  1051  carrying pest sensing circuit  1252 . Pest sensing circuit  1252  includes an electrically conductive loop or network that has an electrical resistance, represented in  FIG. 28  by R 1 . This electrical resistance R 1  is below a predefined level when pest control device  1210  is installed and is subject to alteration by pest activity as previously described for conductor  153  of pest control device  110 . Substrate  1051  and/or pest sensing circuit  1252  include material that is typically displaced or consumed by one or more pests to be monitored with arrangement  1260 . When coupled to circuitry  1220 , pest sensing circuit  1252  cooperates therewith to provide monitoring circuitry  1269 . Pest monitoring arrangement  1260  further includes bait  1032  as previously described in connection with device  1010 , a surface of which is shown by the cut away view in the lower portion of  FIG. 27 . 
     Pest monitoring arrangement  1260  is configured as a portable unit for installation in and removal from housing  1070 , as previously described for device  1010 . Sensor  1250  is fixed in relation to circuit subassembly module  1244  by connector  1040  which is in turn fixed to cap  1280  (shown in section). Also, as described for device  1010 , member  1090  provides further mechanical support for arrangement  1260 , including one or more side members (not shown) connected to module  1244  and/or cap  1280 . Cap  1280  can be configured comparably to cap  1080  of pest control device  1010 , allowing for the mounting of indicators  1136  and  1138  to be visible to an operator external to device  1210 . 
     In  FIG. 28 , circuitry  1220  is shown in a schematic form. Indicators  1136  and  1138  of arrangement  1230  can each be selectively illuminated with circuitry  1220 . Circuitry  1220  also includes electrical energy source  1225  arranged to supply a generally constant voltage, and controller circuit  1240  operatively coupled to source  1225  and indicator arrangement  1230 . 
     Controller circuit  1240  is selectively coupled to pest sensing circuit  1252  by connector  1040 . Controller circuit  1240  can be comprised of one or more components of a digital variety, analog variety, a different variety as would occur to one skilled in the art, or a combination of these. In one form, controller circuit  1240  is based on a solid-state, integrated circuit device. For example, controller circuit  1240  is symbolically illustrated as a single integrated circuit device IC 1  in  FIG. 28 . The illustrated embodiment corresponds to a model number PIC12C5XX microcontroller from Microchip Technology, Inc. This form of microcontroller is of a programmable type, has a Reduced Instruction Set Computer (RISC) processor, and includes one or more forms of memory. Source  1225  can be comprised of one or more electrochemical cells (such as a common battery) that provide approximately a three (3) volt Direct Current (DC) coupled between contacts VDD and VSS to provide power to IC 1  for the depicted embodiment. Connector  1040  is coupled across the GP 4 /OSC 2  and GP 3 /  MCLR /VPP contacts of IC 1 ; and arrangement  1230  is coupled to contacts GP 1 , GP 0 , and GP 2 /TOCK 1 . A data sheet for the PIC12C5XX family of microcontrollers, is hereby incorporated by reference. Alternatively or additionally, in other embodiments a different type of controller circuit of a programmable or nonprogrammable variety can be utilized as would occur to those skilled in the art. 
     Referring generally to  FIGS. 27 and 28 , the operation of pest control device  1210  is next described. Pest control device  1210  is arranged for placement in a region to be monitored for one or more pests as illustrated for various pest control devices in  FIG. 2  and  FIG. 20 . Further, as depicted, pest control device  1210  is suitable for installation in the ground. Indeed, during normal use, one or more pest control devices  1210  can be installed at least partially below ground, with cap  1280  remaining at least partly visible. 
     To conserve power, circuitry  1220  can be arranged such that it is not activated until it is electrically coupled to pest sensing circuit  1252  via connector  1040 . For example, this coupling can cause the closure of a conductive path that triggers activation (such as path  1226  shown in  FIG. 28 ). In one form, a switch could be triggered by the insertion of pest sensing circuit  1252  into connector  1040  and/or an auxiliary conductor provided with pest sensing circuit  1252  to close the electrical path. Alternatively or additionally, circuitry  1220  could be activated by an operator control, such as a manual switch mounted to cap  1280 ; a magnetic or electromagnetic activation signal; an activation/stimulus technique utilized with any of devices  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 , or  1110 ; and/or be arranged to operate without a specific activation requirement. 
     Once activated and installed, controller circuit  1240  of pest control device  1210  operates to automatically monitor the status of pest sensing circuit  1252  on a continuous basis and/or a periodic basis. Controller circuit  1240  is further operable to detect a change in status of pest sensing circuit  1252  from a first state to a second state. In one example, the first state can correspond to an electrically closed circuit with a value of resistance R 1  below an established threshold and the second state can correspond to an electrically open circuit with a value of resistance R 1  above an established threshold. In other examples, one or more different parameters, such as capacitance, inductance, and/or magnetic signature (to name just a few) could be monitored/detected with controller circuit  1240 , and a corresponding change of status of pest sensing circuitry  1252  defined in relation to such one or more different parameters as an addition or alternative to resistance and/or an open/closed circuit condition. 
     For the first state of pest sensing circuit  1252 , controller circuit  1240  outputs a signal via contact GP 0  to indicator  1136  (one of LEDs  1124 ) of arrangement  1230  to cause it to emit light, while indicator  1138  (another of LEDs  1124 ) of arrangement  1230  remains unilluminated. This condition can be considered a first light emitting configuration of arrangement  1230 . Controller circuit  1240  responds to the detection of the change in status of the pest sensing circuit  1252  from the first state to the second state by adjusting its output to discontinue illuminating indicator  1136  via output through contact GP 2 /TOCK 1  and to begin illuminating indicator  1138 . This condition can be considered a second light emitting configuration of arrangement  1230 . 
     In one form, indicator  1136  is a green colored LED  1124  that is pulsed with the output from controller circuit  1240  to intermittently emit light in a blinking pattern and/or vary the intensity of emitted light for the first light emitting configuration; and indicator  1138  is a red colored LED  1124  that is pulsed by the output from controller circuit  1240  to intermittently emit light in a blinking pattern and/or vary intensity of emitted light for the second light emitting configuration. Such blinking patterns can include alternating the light emitting device between an “on state” and an “off state.” A given state of a pest sensor can be represented by a variation in the emitted light that is periodic and/or in accordance with a predefined pattern of variation. Such variation can be based on change in intensity, reflection, direction, refraction, filtering, and/or blocking of the emitted light. In one nonlimiting form, light intensity is varied between two nonzero intensity levels. In other forms, the illumination may be approximately constant for a given state; the coloration type and number of light emitting indicators may vary; and/or the light emitting configurations may be different. 
     It should be understood that when power is no longer available from source  1225 , neither indicator  1136  nor indicator  1138  will illuminate, indicating a power failure. The monitoring of pest sensing circuit  1252 , the detection of a change of state, the adjustment of one or more output signals from controller circuit  1240  to arrangement  1230 , or other operations can be performed in accordance with the operating logic executed by controller circuit  1240 . This operating logic can be in the form of programming instructions, dedicated circuitry, a combination of these, and/or such different forms as would occur to those skilled in the art. By way of nonlimiting example, for the PIC12C5XX controller embodiment previously described, at least a portion of the operating logic is in the form of programming instructions stored in a resident, nonvolatile memory. 
     Through the operation of circuitry  1220 , a two-state signal is provided with indicators  1136  and  1138  that each visually indicates whether or not the electrical continuity/resistance of pest sensing circuit  1252  has been altered relative to an established threshold. This two-state signal can be used to determine when to reconfigure pest control device  1210  to add a pesticide, exchange pest monitoring arrangement  1260  with a pesticide delivery arrangement, and/or prompt another action. Such other actions may include installing additional devices with or without pesticide. In still a further embodiment, pest control device  1210  is configured to initially include a pesticide laden bait so that circuitry  1220  provides information indicative of pesticide consumption. 
     In other embodiments, only a single indicator is used for arrangement  1230 . For one form of this embodiment, an LED only illuminates when pest activity is detected or when pest activity is not detected, but not for both. For another form of this embodiment, a multicolor LED type of indicator is used instead of two discrete LED components. For other embodiments, one or more indicators other than an LED can be used. Such an indicator can be visual, audible, a combination of these, or such different type as would occur to those skilled in the art. In one example, the indicator is in the form of an incandescent lamp or electromechanical indicator. In another example, the indicator is in the form of an RF signal transmitter that outputs information provided by monitoring circuitry  1269  in response to a stimulus. 
     In yet another form,  1220 , source  1225 , indicator(s)  1136  and  1138  and/or other features of circuitry  1220  are configured as a unit that can engage and disengage from the rest of device  1210  by way of a connector or otherwise. For this form, such a unit could be used to interrogate multiple devices  1210  by manually engaging/disengaging each of the multiple devices  1210  in a desired sequence. In a further variation, such a unit could be configured to retain the information from multiple devices  1210 . 
     In further embodiments, source  1225  can be of a form other than a battery, can be external to device  1210  and/or can be selectively applied to device  1210  by an operator. Alternatively or additionally, monitoring circuitry  1269  can be adapted to communicate different information about the device. In another example, controller circuit  1240  and arrangement  1230  can be added to wireless communication circuits of previously described pest control devices. Controller circuit  1240  is adapted to output indications corresponding to different nonzero levels of pest consumption or displacement of bait  1032  and/or corresponding alteration of pest sensing circuit  1252 . Accordingly, information quantitizing the amount of alteration, consumption, and/or displacement can be realized. For such embodiments, the sensor arrangements of devices  310 ,  410 ,  510 ,  610 ,  710 , and/or  810  can be utilized with appropriate adaptations to circuitry  1220 . In one such form, multiple LEDs or another visual display outputs varying nonzero levels of consumption. In still another form, a single two-state indicating LED is utilized; however, a threshold level is set that corresponds to a given nonzero degree of alteration, consumption and/or displacement. This threshold can be factory set and/or set by an operator. 
     Generally, it should be appreciated that embodiments utilizing one or more light emitting indicators can flash, change color, change a blinking pattern, and/or vary intensity of the emitted light in accordance with one or more patterns to represent a given state. Likewise, a changing output pattern can be utilized with other types of output devices such as audible and mechanical indicator types, to name just a few. 
       FIG. 29  illustrates a further type of pest control system  1300  that includes pest control devices  1310  and  1410 , where like reference numerals refer to like features previously described. System  1300  includes building  1412  that houses system data collection device  1460  in the form of a display and control panel  1462 . System  1300  also includes a central data collection site  626  (see  FIG. 20 ) that is connected by communication pathway  1414  to device  1460 . Communication pathway  1414  can be a hardwired connection through a computer network such as the internet, a dedicated telephone interconnection, a wireless link, a combination of these, or such other variety as would occur to those skilled in the art. 
     For system  1300 , pest control devices  1310  are depicted in-ground and pest control device  1410  is depicted within building  1412 . Pest control devices  1310  and  1410  are coupled by bus  1420  to device  1460  to selectively communicate therewith. Central data collection site  626  can be connected to a number of remotely located devices  1460  and/or units  390  (see  FIGS. 11 ,  14 ,  17 , and  20 ). Alternatively or additionally, central data collection site  626  can be arranged to monitor different buildings or areas through such units  390  or devices  1460  with one or more of pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and/or  1410 . 
     Referring additionally to  FIGS. 30 and 31 , a representative pest control device  1310  of system  1300  is further depicted; where like reference numerals refer to like features.  FIG. 31  also illustrates device  1460  in schematic form. Pest control device  1310  includes communication circuitry  1320 , connector  1040 , and sensor  1350  configured in a pest monitoring arrangement  1360  as shown in  FIG. 30 . Communication circuitry  1320  is coupled to bus  1420 . Bus  1420  includes a two-way (bidirectional) communication pathway  1422  (also designated BCP) in the form of electrical conductor  1422   a , a corresponding electrical ground line  1424  (also designated GND) in the form of electrical conductor  1424   a , and a sensing circuit power supply line  1426  (also designated PWR) in the form of electrical conductor  1426   a . As schematically shown in  FIG. 30 , conductors  1422  and  1424  may be a “twisted pair” configuration to assist with electrical noise elimination; however, in other embodiments a different wiring configuration could be utilized. 
     Communication circuitry  1320  includes addressable communication device  1340  connected to pathway  1422  of bus  1420 , and also includes sensing interface  1330  coupled between device  1340  and pest sensing circuit  1352 . The components of communication circuitry  1320  are assembled to provide circuit subassembly module  1344 . Module  1344  can include a printed wiring board to electrically interconnect various components and/or other members to mechanically support communication circuitry  1320 . Module  1344 , and correspondingly communication circuitry  1320 , are electrically and mechanically coupled to sensor  1350  by connector  1040 . Connector  1040  can include an electrically conductive elastomeric material as described for connection members  140  of pest control device  110 , and/or such different materials or configuration as would occur to one skilled in the art. 
     Sensor  1350  includes substrate  1051  carrying pest sensing circuit  1352 . Pest sensing circuit  1352  includes an electrically conductive loop or network that has an electrical resistance below a predefined level when installed and that is subject to alteration by pest activity as previously described for conductor  153  of pest control device  110 . Substrate  1051  and/or pest sensing circuit  1352  include material that is typically displaced or consumed by one or more pests to be monitored with arrangement  1360 . When coupled to communication circuitry  1320 , pest sensing circuit  1352  cooperates therewith to provide monitoring circuitry  1369 . 
     Pest monitoring arrangement  1360  further includes bait  1032 , a surface of which is shown by the cut away view in the lower portion of  FIG. 30 . Bait  1032  can be configured the same as bait member  132  or any previously described variations thereof. In one arrangement, bait  1032  is in the form of at least two members positioned on opposing sides of sensor  1350  as depicted in  FIGS. 3 and 6  for bait members  132  in relation to sensor  150  of pest control device  110 . 
     Pest monitoring arrangement  1360  is configured as a portable unit for installation in and removal from housing  1070 . Housing  1070  can be shaped and composed of material suitable for installation in the ground like housing  170  described in connection with pest control device  110 . Sensor  1350  is fixed in relation to circuit subassembly module  1344  by connector  1040  which is in turn fixed to cap  1380  (shown in section). Carrying member  1090  provides further mechanical support for arrangement  1360 , including one or more side members (not shown) connected to module  1344  and/or cap  1380 . Cap  1380  can be configured comparably to cap  180  of pest control device  110 , with modification to accommodate coupling of conductors  1422   a ,  1424   a , and  1426   a  to device  1310  with connector  1382 . Carrying member  1090  can be configured comparably to carrying member  190  of pest control device  110 , and may be permanently fixed in relation to module  1344  and/or cap  1380 , or selectively connected thereto. 
     Referring specifically to  FIG. 31 , further details of data collection device  1460  and pest control device  1310  are illustrated, it being understood that only one of devices  1310  is shown to enhance clarity. Device  1340  of pest control device  1310  is depicted in the form of an addressable semiconductor switch component provided by Dallas Semiconductor under model number DS2405. For this model, the DATA pin (Shown as BCP pathway connection in  FIGS. 30 and 31 ) is connected to data pathway  1422  of bus  1420 , providing a single bit, bidirectional communication port  1322  therewith. Likewise, the GND pin is connected to the ground line  1424  of bus  1420 . The power supply line  1426  of bus  1420  (providing about 5 volts D.C. in this example), is connected to sensing interface  1330  to provide electrical power thereto. In the illustrated arrangement, device  1340  includes an internal capacitor (not shown) that stores electric charge sufficient to power its internal circuitry. This capacitor parasitically derives its stored energy from the voltage across pathway  1422  and ground line  1424 . Because of this parasitic capacitive power source; device  1340  does not need to draw electrical power from power supply line  1426 . Nonetheless, in other embodiments, device  1340  may additionally or alternatively receive power through a connection to power supply line  1426  and/or a different power source, such as one or more electrochemical cells to name just one example. Likewise, interface  1330  can be powered by more than one source and/or a different source such as one or more electrochemical cells or a capacitor, just to name a few. 
     Each addressable monitoring device  1340  includes a permanent, factory-inscribed identifier  1342  in the form of a binary number. Devices  1340  can be obtained in groups with each identifier  1342  being different from that of any other members in the group. Device  1340  is configured to compare its identifier to information received over bus  1420  to determine if it is being addressed. For a group of addressable communication devices  1340  with different individual identifiers  1342 , each device  1340  can be uniquely addressed over pathway  1422 . Once addressed, a given device  1340  can be interrogated to output the status of a separate input (I/P) node over pathway  1422 —more particularly whether the I/P node is at a high or low binary logic level. For the DS2405 form of device  1340 , the I/P node is a connection pin designated as the “PIO” pin, which is also capable of providing an output in various operating modes as an “open collector” type of node. Additional information concerning the model DS2405 form of device  1340  is provided in the “Dallas Semiconductor DS2405 Addressable Switch” data sheet obtained from the universal resource locator (URL) of www.maxim-ic.com on 16 Jul. 2002. 
     Interface  1330  includes PNP transistor  1332  with a collector connected to the I/P node of device  1340 , an emitter coupled to power supply line  1426 , and a base coupled between one contact of connector  1040  and resistor  1334 . In one embodiment suitable for use with the DS2407 form of device  1340 , transistor  1332  is of a model 2N3906 type and resistor  1334  is of a 220,000 ohm variety. When engaged with connector  1040 , pest sensing circuit  1352  is placed between the base of transistor  1332  and electrical ground. In  FIG. 31 , pest sensing circuit  1352  is represented by resistor  1353 . 
     Referring also to  FIG. 29 , pest control device  1410  is of a type suitable for use in building  1412 , and is adapted to interface with bus  1420  in the manner described for device  1310 . Accordingly, pest control device  1410  could be provided by modifying any of the previously described “in-building” devices  410 ,  510 , and  610  depicted in  FIG. 20  to include monitoring circuitry  1369 . Although  FIG. 29  presents only one pest control device  1410  and several pest control devices  1310 , it should be understood that in other embodiments, more or fewer of each type could be utilized, either with or without one or more of pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 , and/or  1210 . It should be appreciated communication port  1322  of each of the pest control devices  1310 ,  1410  is connected to a common electrical node  1423  provided by conductor  1422   a  of communication pathway  1422 . Likewise, common electrical ground and power connections are shared through conductors  1424   a  and  1426   a , respectively. 
     Data collection device  1460  individually interrogates pest control devices  1310  and  1410  and collects and stores data received in response over bus  1420 . Data collection device  1460  also provides for an operator interface through various operator output devices  1464  and operator input devices  1480 . Output devices  1464  include Liquid Crystal Display (LCD)  1466  capable of displaying designated alphanumeric strings, light emitting device  1468   a  to indicate power status, light emitting device  1468   b  to indicate scan status, light emitting device  1468   c  to indicate fault status, and light emitting device  1468   d  to indicate active status. Devices  1468   a ,  1468   b ,  1468   c , and/or  1468   d  could be of an LED type, incandescent type, a different type, or combination of these types just to name a few. 
     Output devices  1464  are coupled to control circuitry  1470  of device  1460 . Control circuitry  1470  includes controller  1472 , oscillator  1474 , and memory  1476 . Controller  1472  is provided with operating logic in the form of programming instructions, dedicated logic circuitry, a combination of these, or such different forms as would occur to those skilled in the art. Various operations of control circuitry  1470  are implemented with controller  1472  according to this operating logic, including, but not limited to communications over bus  1420 ; data processing, storage, and retrieval; and directing input and output operations. In one embodiment, controller  1472  is of a form provided by Microchip Technologies under model number PIC16F877, with at least a portion of its operating logic provided as programming instructions. Controller  1472  includes a single bit, bidirectional I/O port arrangement to communicate over pathway  1422  of bus  1420 . Oscillator  1474  is of a standard type provided to generate clock signals for operation of controller  1472 . Memory  1476  is shown as being of a nonvolatile Electrically Erasable Programmable Read Only Memory (EEPROM); however, it can be of one or more other types such as a flash memory, battery backed-up Random Access Memory (RAM), magnetic bubble memory, optical or electromagnetic disc, Dynamic RAM (DRAM), and/or Static RAM (SRAM), to name just a few. If a nonvolatile type is used, it could be reloaded as needed from an external device, such as site  626  via pathway  1414  and/or an input device such as a disk drive (not shown). Alternatively or additionally, a personal computer (not shown) could be coupled to device  1460  through which pathway  1414  is established over a computer network, such as the Internet. This personal computer could also or instead provide means to communicate data and/or programming from/to device  1460 . 
     Device  1460  further includes operator input devices  1480  in the form of pushbutton switches  1482 ,  1484 ,  1486 , and  1488  coupled to controller  1472  to provide four unique inputs: up, down, install, and reset, respectively, to control circuitry  1470 . Power supply  1490  is also included that provides electrical power to components of device  1460  and bus  1420 . For an embodiment implemented with the PIC16F877 form of controller  1472 , pins A 0 -A 3  are coupled to devices  1468   a - 1468   d ; pins D 0 -D 7 , E 0 , and E 1  are coupled to LCD  1466 ; and pins B 0 -B 3  are coupled to input devices  1480  in an appropriate manner. 
     Referring generally to  FIGS. 29-31 , various modes of operation of system  1300  are further described. Data collection device  1460  and pest control devices  1310 ,  1410  are arranged for placement in a region to be monitored, such as building  1412  and the region surrounding it. Pest control devices  1310 ,  1410  are installed and coupled to data collection device  1460  by bus  1420 . For the depicted embodiment, pest control device  1310  is suitable for installation in the ground. Indeed, during normal use, one or more pest control devices  1310  are installed at least partially below ground, while pest control device  1410  is installed in building  1412 . Data collection device  1460  is also installed in building  1412  as illustrated in  FIG. 29 . 
     For a group of devices  1310  and  1410  each having a different identifier  1342 , members of this group can each be uniquely addressed as slaves on bus  1420  with respect to a bus master. For system  1300 , the bus master operation is performed in accordance with operating logic of controller  1472 . When a device  1340  is uniquely addressed by controller  1472  over bus  1420 , a protocol is established that permits I/P node status interrogation to be sent by controller  1472 . In response to such interrogation, the uniquely addressed device  1340  transmits the logic state of its corresponding I/P node over pathway  1422  as previously described. 
     The logic state of the I/P node is determined by the status of pest sensing circuit  1352 . If pest sensing circuit  1352  is intact and electrically coupled across the base of transistor  1332  and ground by connector  1040 , the voltage divider formed by resistors  1334  and  1353  presents a voltage across the base and emitter that turns-on transistor  1332 . As previously described in connection with other embodiments, if one or more pests displace material such that pest sensing circuit  1352  becomes electrically open or of a sufficiently greater electrical resistance, then the voltage across the base and emitter decreases to turn-off transistor  1332 . As the on/off status of transistor  1332  changes, so does the logic level presented at the I/P node of device  1340 . 
     The operating logic of controller  1472  recognizes and stores data corresponding to the identifiers  1342  of the group of installed pest control devices  1310 ,  1410 ; where such identifiers  1342  are each unique relative to the others within this group. Installation of individual pest control devices is indicated by an operator with pushbutton  1486 . A list of installed pest control devices  1310 ,  1410  can be generated and displayed with display  1466 . The operator can scroll-up and down this list with pushbuttons  1482  and  1484 , respectively. The control circuitry  1470  can be reset with pushbutton  1488 . 
     The operating logic of controller  1472  is further provided to appropriately illuminate device  1468   a  to indicate power is provided and device  1468   d  to indicate system  1300  is active. Further, in accordance with its programming, controller  1472  periodically scans the coupled pest control devices  1310 ,  1410  one-by-one, interrogating each about the status of the corresponding pest sensing circuit  1352  as reflected by the logic level on the I/P node of the respective device  1340 . Device  1468   b  is illuminated by controller  1472  to indicate this operation. As the pest control devices  1310 ,  1410  are individually addressed, the resulting status is transmitted by the corresponding device  1340  to control circuitry  1470  over pathway  1422  and stored. The list of installed pest control devices  1310 ,  1410  presented with display  1466  is updated to reflect: (1) if it is “active” and (2) if pest presence is indicated by a change in state of the I/P node of one or more of devices  1310 ,  1410 . The “active” status of a given device  1310  or  1410  can be indicated by a switch or other circuit function that changes in response to the mechanical connection of substrate  1051  to connector  1040  as previously described in connection with pest control device  1210 . 
     If a change in state indicative of pest presence occurs, a fault is indicated and controller  1472  is programmed to illuminate device  1468   c  to indicate a “fault” condition. A corresponding audible alarm could alternatively or additionally be generated (not shown). If not apparent from the information shown with display  1466 , the fault indication can prompt an operator to scroll through the list to find any pest control devices with a fault. 
     Once the presence of one or more pests is determined, one mode of operation reports the fault to a central data site  626  via pathway  1414  and/or causes a pest control service provider to inspect system  1300  and take further action as deemed appropriate. Alternatively or additionally, an operator at building  1412  can report the fault to a pest control service provider. In another mode, the occupant of building  1412  can address the detection of pests without notifying a remotely located pest control service provider. The actions that might be taken by the operator and/or a notified pest control service provider include reconfiguring one or more of pest control devices  1310 ,  1410  to add a pesticide by exchanging pest monitoring arrangement  1360  with a pesticide delivery arrangement. Other actions may include installing additional devices with or without pesticide. In still a further embodiment, pest control device  1310 ,  1410  is configured to initially include a pesticide laden bait so that communication circuitry  1320  provides information indicative of pesticide consumption. 
     In a different embodiment, the I/P node is interfaced to pest sensing circuit  1352  without a transistor. In still other embodiments, different resistor values and/or a different type of switching device is used in addition or as an alternative to transistor  1332 . Such alternative arrangements can include an NPN bipolar junction transistor, a Field Effect Transistor (FET), an electromechanical relay, or a Solid State Relay (SSR) in place of PNP transistor  1332  with corresponding adjustments to circuitry  1320 , to name only a few possibilities. 
     In other embodiments, addressable communication device  1340  is of type other than model DS2405 and/or provided by custom circuitry comprised of one or more components suitable to interface with pest sensing circuit  1352  directly or through interface  1330 . In one such alternative, identifiers  1342  of each of devices  1310 ,  1410  can be assigned or changed electronically and/or mechanically. In another alternative, monitoring circuitry  1369  and/or device  1340  is adapted to communicate different information about the device, such as changes in nonzero levels of pest consumption or displacement to quantitize the amount of consumption or displacement realized. For such embodiments, the sensor arrangements of devices  310 ,  410 ,  510 ,  610 ,  710 , and/or  810  can be utilized with appropriate adaptations to communication circuitry  1320 . Further, multiple devices  1340  can be used in the same pest control device with appropriate support circuitry to reflect different discrete levels of consumption or displacement. 
     Controller  1472  can be provided by a type other than a PIC16F877, and/or comprised of one or more components suitably arranged to perform the operations described in connection with control circuitry  1470 . Correspondingly, support components such as oscillator  1474  and/or memory  1476  can differ, be used with other components, or may be absent. Different types of output devices  1464  can be used in other embodiments such as a plasma display, electromechanical indicators, or a Cathode Ray Tube (CRT), to name only a few. Different types of input devices  1480  can be used in other embodiments such as toggle switches, an alphanumeric keyboard or keypad, a pointing device such as a noise or light pin used in concert with a display, or a voice recognition subsystem, to name just a few. 
     In other embodiments, bus  1420  can be of an optical variety using an optic fiber or other transmission means. Alternatively, bus  1420  can be arranged with one-way communication along a given pathway rather then being bidirectional in all embodiments. For such an example, multiple communication pathways can be used with at least one pathway being master-to-slave and another being slave-to-master. Also, further embodiments can be configured for a parallel communication format as an additional or alternative to serial communication. Likewise, any compatible bus protocol can be used. 
     In still another form, communication circuitry  1320  and/or control circuitry  1470  are provided in the form of a wireless signal transponder that can be active or passive in nature. In a further variation, communication circuitry  1320  and/or control circuitry  1470  is adapted to provide for wireless and/or manual interrogation using techniques of previously described embodiments. 
     In still other embodiments, pest control devices  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , or  1410  can include one or more bait members  132  as described in connection with pest control device  110  of system  20 . Furthermore, any of pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and  1410  can be configured for in-ground placement, on-ground placement, or above-ground placement. In another embodiment, a pest control device is adapted to combine the sensing techniques of two or more of pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , or  1410 . Additionally or alternatively, two or more different types of pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and  1410  can be used to monitor pest activity and/or deliver pesticide in a common region. 
     In further embodiments, pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , or  1410  can be arranged to be completely or partially replaced by a pesticide delivery device once pests are detected. This replacement can include removing a communication circuit module or other circuitry from a pest monitoring arrangement for incorporation into a pesticide delivery arrangement. Any of pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , or  1410  can be configured to simultaneously monitor pest activity and deliver pesticides in other embodiments. Alternatively or additionally, pest control devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and/or  1410  can be configured to automatically deliver pesticide once a given degree of pest consumption or displacement is detected. For this arrangement, delivery can be triggered automatically in accordance with monitoring data and/or by an external command received via a communication circuit. 
     The flowchart of  FIG. 32  depicts procedure  920  of yet another embodiment of the present invention. In stage  922  of process  920 , data is collected from one or more devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and/or  1410 . In stage  924 , gathered data is analyzed relative to environmental conditions and/or location. Next, pest behavior is predicted from this analysis in stage  926 . In accordance with the predictions of stage  926 , action is taken in stage  928  that may include installation of one or more additional devices. 
     Next, loop  930  is entered with stage  932 . In stage  932 , data collection from devices continues and pest behavior predictions are refined in stage  934 . Control then flows to conditional  936  that tests whether to continue procedure  920 . If procedure  920  is to continue, loop  930  returns to stage  932 . If procedure  920  is to terminate in accordance with the test of conditional  936 , the procedure is then halted. 
     Examples of other actions that may be additionally or alternatively performed in association with stage  928  include the application of pest behavior patterns to better determine the direction pests may be spreading in a given region. Accordingly, warnings based on this prediction may be provided. Also, advertising and marketing of pest control systems can target sites that, based on procedure  920 , are more likely to benefit. Further, this information may be evaluated to determine if the demand for pest control servicing in accordance with one or more embodiments of the present invention seasonally fluctuates. Allocation of pest control resources, such as equipment or personnel, may be adjusted accordingly. Further, the placement efficiency of pest control devices may be enhanced. 
     In other alternative embodiments, devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and  1410 , and corresponding interrogators, data collection units and data collectors may be used in various other system combinations as would occur to one skilled in the art. While Interrogator  30  and wand  1102  are each shown in a hand-held form, in other embodiments, such interrogation devices can be in a different form, carried by a vehicle, or installed in a generally permanent location. Indeed, a data collection unit can be utilized to directly interrogate/receive information from a pest control device. Also, while bait for devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and  1410  may be provided in an edible form suitable for termites, a bait variety selected to control a different type of pest, insect or non-insect, may be selected and the device housing and other characteristics adjusted to suit monitoring and extermination of the different type of pest. Moreover, bait for devices  110 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  1010 ,  1110 ,  1210 ,  1310 , and  1410  may be of a material selected to attract the targeted species of pest that is not substantially consumed by the pest. In one alternative, one or more pest control devices include non-food material that is displaced or altered by targeted pests. By way of nonlimiting example, this type of material may be used to form a non-consumable sensing member substrate with or without consumable bait members. Moreover, any of the pest control devices of the present invention can include one or more components that are potted with a polyurethane or other appropriate resin, or coated with epoxy or other appropriate resin to reduce the intrusion of moisture. In one alternative embodiment of that illustrated in  FIGS. 3-5 , there is no inner lip  123  of cover piece  120  and o-ring  124  is absent. For this alternative embodiment, base  130  is ultrasonically welded to cover piece  120  and a polyurethane potting material is utilized to fill any unoccupied space remaining in cavity  122  after assembly of circuit enclosure  118  to reduce moisture contact with circuitry  160 . However, it should be appreciated that in other embodiments of the present invention, it may not be desirable to address intrusion of moisture or another substance in this manner, it my be addressed in a different manner as would occur to those skilled in the art, or it may not be addressed at all. 
     In further alternatives, one or more pest control devices according to the present invention lack a housing, such as housing  170  or housing  1070  (and correspondingly cap  180 , cap  1080 , cap  1180 , cap  1280 , or cap  1380 ). Instead, for this embodiment the housing contents may be placed directly in the ground, on a member of a building to be monitored, or arranged in a different configuration as would occur to those skilled in the art. Also, any of the pest control devices of the present invention may be alternatively arranged so that bait consumption or displacement of a sensing member causes movement of a conductor to close an electrical pathway instead of causing an open circuit. 
     Pest control devices based on wireless communication techniques may alternatively or additionally include hardwired communication connections to interrogators, data collection units, data collectors, or such other devices as would occur to those skilled in the art. Hardwired communication may be used as an alternative to wireless communication for diagnostic purposes, when wireless communication is hampered by local conditions, or when a hardwired connection is otherwise desired. Moreover process  220  and procedure  920  may be performed with various stages, operations, and conditionals being resequenced, altered, rearranged, substituted, deleted, duplicated, combined, or added to other processes as would occur to those skilled in the art without departing from the spirit of the present invention. 
     In another embodiment, a pest control device includes circuitry coupled to one or more sensing elements with one or more elastomeric connection members. The one or more elastomeric connection members can be comprised of a carbon-containing synthetic compound, such as silicone rubber. 
     For still a further embodiment, a pest control device includes a bait operable to be consumed or displaced by one or more species of pest, a pest sensing circuit proximate to the bait, and an indicator arrangement. Also included is a controller circuit operatively coupled to the pest sensing circuit and indicator arrangement that monitors the pest sensing circuit, detects a change of status of the pest sensing circuit, and provides one or more signals to the indicator arrangement corresponding to this change of status. The indicator arrangement changes its output in response to these one or more signals. This embodiment may further include a structure operable to at least partially enclose the bait, the pest sensing circuit, and the controller circuit; and which is further arranged to position at least a portion of the indicator arrangement to be visible to an operator. In one form, the indicator arrangement is comprised of two light emitting components where one of these components is at least intermittently illuminated before the change of status and another of these components is at least intermittently illuminated after the change of status. Other embodiments include a system comprising several such pest control devices. 
     Yet another embodiment includes: installing a plurality of pest control devices each including a respective bait for one or more species of pest; a respective pest sensing circuit; a respective indicator arrangement; and a respective controller circuit; indicating a first state of one of the pest control devices with the respective indicator arrangement; detecting a change in status of the respective pest sensing circuit with the respective controller circuit; adjusting one or more output signals from the respective controller circuit in response to the change in status; and indicating a second state of the one of the pest control devices with the respective indicator arrangement in response to this adjustment. 
     A further embodiment of the present invention includes a group of pest control devices. These devices each have a bidirectional communication port, a pest sensing circuit to detect activity of one or more species of pests, a bait, and an identifier that is unique in relation to the identifier of any other of the devices in the group. A bidirectional communication pathway connects the bidirectional communication port of each of the pest control devices to a data collection device. The data collection device is operable to address a selected one of the pest control devices over the bidirectional communication pathway based on uniqueness of the identifier of the selected one of the pest control devices and receive status of the pest sensing circuit of the selected one of the pest control devices. 
     Yet a further embodiment of the present invention includes: operating a data collection device coupled to a group of pest control devices by a communication pathway, the pest control devices each including a communication port, a pest sensing circuit, and an address unique in relation to the address of any other of the pest control devices in the group; sensing termites with the pest sensing circuit of one of the pest control devices; and receiving sensed information from the one of the pest control devices in response to transmitting an address from the data collection device. 
     Yet still a further embodiment of the present invention includes: operating a plurality of pest control devices each including a bait for one or more species of pest; a respective pest sensing circuit; a respective visual indicator arrangement; and a respective controller circuit; and providing light from the respective visual indicator arrangement of one of the pest control devices in accordance with a periodic pattern of variation to represent one state of the one of the pest control devices. 
     Another form includes: installing a plurality of pest control devices each including a bait, a pest sensing circuit; a visual indicator arrangement, and a controller circuit; emitting light of a first color from the indicator arrangement of one of the devices to represent a first state; detecting a change in status of the pest sensing circuit of the one of the pest control devices; adjusting one or more output signals from the controller circuit for the one of the pest control devices in response to the change in status; and emitting light of a second color different than the first color from the visual indicator arrangement of the one of the pest control device to represent a second state of the respective pest sensing circuit different than the first state. 
     All publications, patents, and patent applications cited in this specification are herein incorporated by reference as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference and set forth in its entirety herein, including but not limited to, U.S. patent application Ser. No. 10/103,460 filed 21 Mar. 2002, U.S. patent application Ser. No. 09/925,392 filed 9 Aug. 2001, International Patent Application Number PCT/US00/26373 filed 25 Sep. 2000, International Patent Application Number PCT/US99/16519 filed 21 Jul. 1999, U.S. patent application Ser. No. 09/669,316 filed 25 Sep. 2000, and U.S. patent application Ser. No. 09/812,302 filed 20 Mar. 2001. Further, any theory, proposed mechanism of operation, or finding stated herein is meant to further enhance understanding of the present invention, and is not intended to in any way limit the present invention to such theory, proposed mechanism of operation, or finding. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the selected embodiments have been shown and described and that all changes, equivalents, and modifications that come within the scope of the invention defined herein or by following claims are desired to be protected.