Abstract:
Bait stations are provided which present the ability to monitor bait and expand capacity of bait without materially adversely affecting feeding activity. In one form a slow acting toxicant-laced attractant is provided in the station. The station has an outer housing, an openable opaque lid, and a transparent window moveable relative to both the lid and housing. One can move the lid while leaving the window in place, or move both the lid and window. Removal of both permits attachment of a second such housing to the first, while the first remains in place. The lid and window can then be affixed to the second housing. These stations can be used to control termites and other crawling pests.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not applicable  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT  
       [0002]     Not applicable  
       BACKGROUND OF THE INVENTION  
       [0003]     The present invention relates to bait stations for controlling unwanted pests, such as termites. More specifically, it relates to bait stations that (i) permit one to monitor feeding progress, and (ii) to vary the capacity of the station once feeding has begun, with minimum adverse effect on the feeding as a result thereof.  
         [0004]     In many areas of the world homes and businesses experience pest infestations such as termite infestations and other crawling insect infestations. Termites not only nest in buildings, they also tend to destroy those buildings over time as they feed on wood.  
         [0005]     Controlling termites in buildings can be difficult as termites tend to burrow deep into wood structures. Hence, merely placing a toxic bait at a random position in a room would normally be ineffective in controlling termites, particularly if the toxic material is fast acting. In this regard, termites may find the entire wood structure of the building to be an equally desirable “bait”, and thus may not be significantly influenced by yet another randomly positioned cellulose source (especially if it is not convenient to their normal path of travel). Further, even if a particular termite happens to feed on a toxic bait, that may do little to control the remaining population if the termite dies quickly near the bait.  
         [0006]     One approach for controlling termites that has had some success takes advantage of the fact that termites often repetitively travel along a given preferred pathway, and the fact that termites often ingest the food, and then later regurgitate it along that pathway or at their nest. Hence, a bait can be positioned along a frequently used termite “trail”, and be provided with a slower acting toxicant. “Termite trail” is used to refer to both enclosed termite tunnels and also at least partially open trails.  
         [0007]     Positioning of a bait station adjacent a trail, which may be visible along a stucco wall for example, improves the likelihood that the termite will choose to feed at a bait station. Further, the use of the slower acting toxicant helps insure that termites that feed at the station will not immediately be killed at the station. Rather, there will be enough time for the termite to return to the nest and/or trail and regurgitate at those sites. Then, other termites will be likely to encounter the regurgitated bait and feed on it.  
         [0008]     A complicating factor in designing bait stations that use this approach is that termites tend to avoid light and also prefer relatively constant environmental conditions (e.g. temperature; humidity) when feeding. When they are faced with a sudden light source, or an altered environmental condition, they scatter to a known safer place. This can be particularly problematic when one wants to check a bait station to determine if the bait has been used up or if alternatively no termites have been attracted.  
         [0009]     In U.S. Pat. Nos. 6,058,646 and 6,079,151 there was disclosed a termite bait station in the form of a box-like housing that was positioned against selected walls or floors. The bottom of the housing had an entry positionable adjacent a termite trail. The interior of the housing contained an edible toxic material for controlling the termites. A removable cover was provided to allow for inspection of the housing interior and/or assembly of a second stacked housing.  
         [0010]     However, upon removal of the exterior cover, the interior of the housing and associated bait would be exposed to ambient conditions. Thus, even if the cover were removed in extremely low light conditions, termites feeding inside the housing could be “spooked” by a rush of fresh or different temperature or humidity air caused by the cover removal. Thus, inspecting the cavity interior to see if the station was working, and/or whether the bait was completely consumed, could disrupt the function of the station.  
         [0011]     As such it can be seen that a need still exists for improved bait stations, particularly those stations that allow for monitoring of the station and expanding of its capacity, both without significantly adversely affecting on-going feeding.  
       BRIEF SUMMARY OF THE INVENTION  
       [0012]     In one aspect the invention provides a bait station having a housing suitable to contain bait for a pest (preferably a termite or other crawling insect). The housing has an entry to permit the pest to enter and access the bait if the bait is positioned in the housing. The housing also has an open (preferably outward) end.  
         [0013]     A window is positioned so as to cover over at least a portion of the open end of the housing, and a lid is mountable to the housing so as to essentially cover the window. The lid can be moved from a first position where light is inhibited by the lid from passing through the window from outside the housing to a second position where the housing interior can be inspected through the window. The window is movable relative to the housing and also relative to the lid.  
         [0014]     In preferred forms, the window, when mounted to cover the open outward end of the housing, restricts air entry into an interior of the housing through the open end. This is particularly important when the pest is a termite, the bait is a cellulosic material, and the station is configured to cover a portion of a termite trail. The housing can be in the form of a five-sided box with one of the sides being a base, and two openings being provided on opposed ends of the box adjacent the base to accommodate a termite trail.  
         [0015]     In particularly preferred forms the window can be a transparent or translucent wall and the lid can be completely opaque. The window permits viewing of the bait and termite activity relative thereto, without disturbing the environment around the bait. When the lid covers the window it preferably will block essentially all light from passing through the window to the baiting area.  
         [0016]     The window is movable such that bait can be added to the interior of the housing. It can be a separate part, or it can be connected by a living hinge to the housing.  
         [0017]     In another aspect the invention provides a kit for alternatively assembling a bait station in either a stacked or unstacked assembly. The kit has a first housing suitable to contain bait for a pest. The first housing also has an entry to permit the pest to enter the first housing and access the bait if bait is positioned in the first housing interior. The first housing also has an open outward end. A window and a lid are also provided.  
         [0018]     A second housing is provided having opposed open ends (one outward and one inward). The second housing is positionable to create a stacked array by being positioned against the first housing&#39;s outward end when an inward end of the second housing is positioned adjacent the first housing&#39;s outward end. The second housing also is configured so that it may contain bait for a pest in its interior.  
         [0019]     The window can be alternatively positioned to cover over either the open outward end of the first housing or the open outward end of the second housing. The lid can be positioned adjacent the window and can be moved from a first position where an interior of a housing can be viewed through the window to a second position where that interior cannot be viewed through the window (and light is inhibited from passing through the window).  
         [0020]     In preferred forms the window, when mounted to cover an open end of a specified housing, restricts air entry into the interior of that housing through that open end, the first housing is in the form of a five-sided box with one of the sides being a base, two openings are provided on opposed ends of the box adjacent the base (e.g. to accommodate trail), the window is a transparent or translucent wall, and the lid is opaque. In preferred use a termite bait and a termite control active ingredient are positioned in an interior of at least one of the housings.  
         [0021]     In another aspect the invention provides methods for controlling termites. One obtains a bait station of the above type. One then places the bait station adjacent a termite trail. One may then move the lid to monitor the status of the bait, and thereafter move the lid again to create a darkened interior of the housing adjacent the bait.  
         [0022]     In preferred aspects of these methods there may also be a further step of removing the window and lid from a first housing, mounting a second housing on the first housing to create a stacked assembly, and then mounting the window and lid on the second housing. This would be desirable if one learned the bait was not completely, but was almost, used up in the first housing. One could then stack on a second bait source, without having to continuously monitor the first housing to determine exactly when it has been completely used up.  
         [0023]     Yet another possible variant of the method includes the additional step of removing the window and lid to provide access to a housing interior, and then adding additional bait to the housing. One then replaces the window and lid.  
         [0024]     The present invention therefore provides bait stations that can be monitored with minimal disturbance to termites or other pests, and methods for using them. The capacity of these stations can be expanded quickly (e.g. if the station is particularly successful). The stations can be manufactured inexpensively, and easily assembled/installed. Further, they are suitable to be affixed by screws or other means to vertical or horizontal walls, thereby providing great flexibility in use.  
         [0025]     The foregoing and other advantages of the present invention will be apparent from the following description. In that description reference is made to the accompanying drawings which form a part thereof, and in which there is shown by way of illustration, and not limitation, preferred embodiments of the invention. Such embodiments do not necessarily represent the full scope of the invention, and reference should therefore be made to the claims herein for interpreting the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIG. 1  is an exploded perspective view of a bait station of the present invention;  
         [0027]      FIG. 2  is an assembled view of the  FIG. 1  bait station, taken from the same perspective as shown in  FIG. 1 , albeit with a termite trail environment also shown;  
         [0028]      FIG. 3  is a bottom perspective view of the  FIG. 1  bait station;  
         [0029]      FIG. 4  is an exploded perspective view of another embodiment of the present invention, having two baiting housings stackable one upon the other;  
         [0030]      FIG. 5  is a partial cross sectional view taken substantially along line  5 - 5  of  FIG. 4  once the  FIG. 4  structure has been fully assembled; and  
         [0031]      FIG. 6  is a front view of a point-of-sale rack containing a termite control kit and refill kit.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]      FIG. 1  shows an unassembled termite bait station  100  having a housing  102 , a window  104 , and a lid  106 . Lid  106  may be a rigid, plastic, opaque structure mountable on an open end  99  of the housing  102 . The window  104  may be made of transparent glass, but may instead be made of a variety of other transparent or translucent materials such as plastics. Window  104  may also be slightly smoked or colored to further reduce the transmittal of certain light frequencies that are the most disturbing to termites.  
         [0033]     The lid  106  can be attached to the housing  102  by frictional engagement, or by snaps, buttons, hook-and-eye fasteners or the like. Lid  106  may be separately formed from the housing  102 , or where only one housing is used be attached by a living or other hinge arrangement to the housing  102  (not shown).  
         [0034]     Housing  102  includes a sidewall  107 , a planar base  108  from which the sidewall upwardly extends, a base entry  109 , an adhesive layer  110 , mounting tabs  112 , a first opening  114 , a second opening  116 , window supports  118 , connection means  120  (see also  126 / 128 ), and lid fastener slots  122 . The housing has an interior cavity  123  for receiving the bait. Each opening  114 ,  116  in a sidewall  107  may initially be open to define a path  200  ( FIG. 2 ) or may initially be closed by removable perforated sections  124  that can be individually removed to create (or enlarge) path  200  to accommodate a termite trail.  
         [0035]     At the upper edge of the housing  102  are stacking tabs  126  which are designed to fit into corresponding slots  128  when the housings are stacked on each other. Window  104  includes a plate section  130 , handles  132 , clearance notches  134  and posts  136 . Lid  106  includes a main plate section  138 , lid fasteners  140 , a lip  142 , and fastener mount apertures  144 .  
         [0036]     Each mounting tab  112  has an aperture  146 . Each lid fastener  140  includes a fastener arm  148  and a knob  150 , the fastener knob being so shaped or textured as to allow ready turning, either by hand or by the use of a coin in a slot, a screw driver, or the like.  
         [0037]     Housing  102  can be affixed to a floor  202 , vertical wall, or the like, and in any event holds bait  204  in cavity  123  for feeding and poisoning termites  208 . Base  108  on the bottom of the housing  102  is coupled to sidewall  107 . Sidewall  107  extends upward from the periphery of base  108 . Base  108  and sidewall  107  together form the five sided body of the housing and define the interior bait cavity  123 .  
         [0038]     Sidewall  107  defines an outward end opening  152  into the bait chamber into which window  104  is mounted, and through which additional bait may be added when the window is moved out of the way. When the window is in the fully assembled position, it acts to essentially close off the interior of the housing from ambient air coming from the opposite side of the window. Nevertheless, one can view the status of the bait through the window.  
         [0039]     In an alternative configuration (not shown), sidewall  107  may extend inwardly somewhat at its top to reduce the size of opening  152 . However, the window should still at least cover a portion of the open end.  
         [0040]     Each of the four mounting tabs  112  and adhesive layer  110  may be configured to facilitate affixing housing  102  to the floor  202   
         [0041]     Adhesive layer  110  is fixed to the bottom of base  108 , and preferably covers the majority of the area of base  108 . Adhesive layer  110  may be initially provided with a release paper (not shown) that the user peels off to expose a sticky bottom surface.  
         [0042]     Connection means  120  are used to fix two housings  102 ,  102 ′ together (see  FIG. 3 ). In this regard, stacking tabs  126  extend upward from a top edge of sidewall  107  on opposite sides of housing  102  and are configured to extend through a slot  400 ′ ( FIG. 5 ) in the bottom of an identically constructed abutting second housing  102 ′ ( FIGS. 3-5 ). Note also the similar slots  400  on the first housing  102 . The tabs  126  each engage a slot  128 ′ of housing  102 ′.  
         [0043]     Four supports  118  protrude from the sidewall  107  and planar base  108  of the housing  102 , and extend from the planar base upward to within 4.0 to 8.0 millimeters of the opening  152 . The supports are located adjacent to the four corners of housing  102 . Each such support has a hole  154  in the top of the support of sufficient size and shape to receive a post  136 , and thereby support window  104 . Window  104  is press-fit into the housing  102  by aligning the window posts  136  with the post holes  154  on window supports  118  while holding the window substantially parallel with the opening  152 , then pushing down on the window until the posts are secured to the post holes.  
         [0044]     Clearance notches  134  are located in opposite ends of the plate section  130 , such that when the window  104  is pressed down, plate section  130  clears stacking tabs  126 . To remove window  104 , the user grasps the handles  132  and pulls the window upward, pulling posts  136  out of post holes  154 . The handles  132  also may be employed to hold the main plate section  138  away from the plate section  130  and provide more structural strength to the window  104  and lid  106 .  
         [0045]     Lid  106  is preferably opaque to completely block light from entering the cavity  123  when it is covering the window and housing opening. In this regard, the main plate section  138  of lid  106  extends completely across the window  104  parallel with plate section  130  when the parts are in their normal position.  
         [0046]     Lid fasteners  140  are mounted in the fastener mount apertures  144  such that each fastener knob  150  extends outside the cover plate and is accessible by the user. Fastener arm  148  is coupled to the fastener knob  150  and extends generally coplanar with and between main plate section  138  and plate section  130 . When the user rotates fastener knob  150 , fastener arm  148  pivots to engage and disengage with slots  122  in sidewall  107  of housing  102 .  
         [0047]     To attach lid  106  and block light from the cavity  123  the user aligns the lid  106  with the housing  102  and presses the lid downward onto the housing firmly. Lip  142  extends over the edge of the housing  102  and turns downward, enclosing opening  152 . The user then rotates the fastener knobs  150 , causing the fastener arms  148  to pivot into the lid fastener slots  122  located on the sidewall  107  of the housing  102 . This locks lid  106  onto housing  102 . Light is thereby blocked from entering bait cavity  123  through window  104  by the opaque main plate section  138 .  
         [0048]     While the housing is unassembled ( FIG. 1 ) the user fills the bait cavity  123  with bait  204 , preferably through the opening  152 . The bait  204  is preferably an attractant made of cellulose fiber or wood pellets, mixed with a termite control active ingredient.  
         [0049]     In this regard, certain fungal and/or bacterial materials are known to be particularly effective termite control active ingredients. For example, Mycopesticide LLC of Shelton, Wash. sells a Metarhizium anisopliae preparation for this purpose. Some synthetic insecticides may also be useful as effective termite control active ingredients. These include but are not limited to Indoxacarb (sold by E. I. du Pont de Nemours and Company) and Fipronil (sold by Rhone Poulenc AG Company).  
         [0050]     Chitin synthesis inhibitors can also be usefully employed for this purpose. A chitin synthesis inhibitor prevents the termite from forming a new exoskeleton during the natural molting process, thereby killing the termite. This is a desirable “slow” acting system. Common chitin synthesis inhibitors include diflubenzuron, chlorfluazuron, hexaflumuron, and noviflumuron. Our wood fiber bait  204  is most preferably impregnated with a 0.5% by weight solution of hexaflumuron solution, which is a benzylurea insecticide.  
         [0051]     The termite trail  206  is shown as formed by termites  208  from regurgitated cellulose and is relatively thin and opaque. The path  200  preferably partially surrounds the termite trail  206 , therefore affixing the bait station  100  to the structure in a way that does not initially break or harm the termite trail.  
         [0052]      FIG. 2  shows a termite  208  which has sensed the bait  204 , eaten a hole  214  through outer wall of the trail  206 , entered the bait cavity  123  through the base entry  109 , and is searching for the bait. However, there is very little bait left as shown in  FIG. 2 . In accordance with the present invention the consumer can nevertheless check the amount of bait  204  remaining in the bait cavity  123  simply by removing the lid  106 .  
         [0053]     Lid removal is relatively fast and can be done when the surrounding area is fairly, but not completely dark. The status of the bait can then be viewed without materially changing the humidity level or temperature in the bait station. Admittedly, there will be some light reaching the bait cavity  123  when monitoring occurs. However, it occurs for only a brief period while the user does a quick visual check. Further, appropriate smoking or tinting of the window can remove particularly problematic light frequencies.  
         [0054]     If there is insufficient bait  204  in the bait cavity  123 , the user can either remove the window  104  and fill the bait cavity  123  with more bait through the opening  152 , or remove the window and stack another pre-filled housing  102 ′ on top of the existing housing  102 , as seen in  FIG. 3 . if no activity is seen in the station during this monitoring, the station can be moved to a possibly more productive position.  
         [0055]     In  FIG. 3 a  second housing  102 ′ is shown with parts that are comparable to the first housing identified with a prime (e.g.  102  versus  102 ′). Note that the second housing  102 ′ can be assembled on the first without removing the first housing from the floor  202 . The user merely removes the lid  106  from the housing  102  by first rotating the fastener knobs  150 , causing the fastener arms  148  to pivot away from and out of the lid fastener slots  122 , and then pulling the lid off the housing.  
         [0056]     The user then removes the window  104  from the housing  102  by grasping the handles  132  and pulling the posts  136  out of the post holes  154 . The user then aligns the second housing  102 ′ above the first housing  102  such that slots  128 ′ and slots  400 ′ ( FIG. 4 ) on the second housing are immediately above the stacking tabs  126  on the first housing.  
         [0057]     Once the housings are in this relative position, the user can press the second housing  102 ′ down, causing the tabs  126  to snap into the slots  128 ′, coupling the second housing  102 ′ to the first housing  102 . This coupled together arrangement is best shown in  FIG. 5 . The user then press fits window  104  onto the second housing  102 ′ and then screws the lid  106  onto housing  102 ′. Because of the large base opening  109 ′ in the second housing  102 ′, the interiors of the housings  102 ,  102 ′ are then essentially contiguous and the housings are in interior communication. This permits termites who have essentially eaten up all the bait in the first housing  102  to be enticed into feeding on the bait in second housing  102 ′.  
         [0058]     Importantly, the process of stacking a new bait station on top of an existing mounted bait station does not disrupt the termite trail. The stacking procedure is also relatively quick, thereby minimizing the environmental disturbance of termites.  
         [0059]     In  FIG. 6 a  termite control kit  600  is shown hanging from a point-of-sale rack  602  by a hook  604 . The kit  600  includes a bait station  100  and a refill  606 . The refill  606  includes termite bait  204  and a bait bag  608 . The bait bag  608  keeps the bait  204  fresh, and therefore hermetically seals the bait. The bait bag  608  is preferably of material that will resist diffusion through the bag wall, such as Mylar, foil or plastic. An alternative refill kit  612  for refilling existing bait stations includes a package  610  enclosing one or more refills  606 , but not including a bait station  100 .  
         [0060]     While the present invention has been described above with reference to what are currently considered to be its preferred embodiments, it is to be understood that the invention is not limited to just those specific embodiments. For example, the bait station could be designed for use with other pests (e.g. preferably other crawling insects such as cockroaches). In such a case, the baiting material and the toxin would be correspondingly altered to be optimized for the insect being targeted. In another variant, openings  114 ,  116  may instead include a slidable panel, a bendable panel or a hinged panel, or be deleted entirely.  
         [0061]     Thus, the invention is intended to cover a wide variety of modifications within the spirit of the appended claims. Hence, the claims are not to be limited to just the preferred embodiments.  
       INDUSTRIAL APPLICABILITY  
       [0062]     The present invention provides single and multiple housing bait stations for controlling termites and other crawling insects, and methods for their use, where the stations permit monitoring of the bait and altering bait capacity with minimal disruption of feeding.