Abstract:
A pre-baited consumer bait station for rodents which is gnaw resistant and has other design features to make the bait station resistant to rodenticide access by children, dogs, other pets, domestic animals, and nontarget wildlife. An injection molded translucent cover is permanently locked to a base about the cover&#39;s edges and center by elastic actuated hooks which engage receptacles on the base. The cover forms a labyrinth joint with a peripheral wall of the base. Double walls on exterior portions of the peripheral wall strengthen the walls where they form part of a closely confining bait receptacle which surrounds a bait block on portions of all sides. Circuitous internal passageways limit access to the bait. An interior wall extends to support the cover center.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to rodent bait stations in general and rodent bait stations for consumer use in particular. 
     Rodenticides can be particularly effective in treating infestations of rodent pests. Bait stations provide an effective mechanism for isolating the rodenticide from children, dogs, other pets, domestic animals, and non-target wildlife. Because the bait associated with the rodenticide can be attractive to non-targeted species, it is desirable to limit access to the rodenticide to dogs, for example, which can devote extended time to gaining entry to a container. Bait stations should not only obstruct the physical entry of the non-targeted species into the station, but also make it difficult for a pet to gain access to the interior by chewing or gnawing on the station. The bait station should also limit the access of children to the bait within. 
     SUMMARY OF THE INVENTION 
     The bait station of this invention is a pre-baited consumer item sized either for mice or rats. The gnaw resistant bait station of this invention incorporates one or more design features in order to make the bait station resistant to pets or people coming into contact with the bait contained within. The bait station is constructed of two injection molded parts, a base part and cover part, which are locked together without provision for opening. The base has a floor and a peripheral wall extending upwardly from the floor. The cover is assembled to overlie the peripheral wall and has a plurality of hooked prongs which engage with retaining receptacles on the base typically along the peripheral wall. The hooked prongs are elastically deformed as the hooks are pressed into receptacles until a hook surface is free to move laterally to engage a lateral surface on the base which locks the hooked prongs to the base. A plurality of such hooked prongs are spaced along the periphery so that no substantial portion of the cover is not locked to the peripheral wall. Because no access is provided to the prongs from the outside, the locking engagement is essentially permanent. At least one hooked prong extends from the approximate center of the cover to structurally tie the interior of the cover to the base. The cover forms a labyrinth joint with the peripheral wall such that a knife blade, a fingernail, or canine incisor cannot easily pass between the cover and the peripheral wall. A canine can act as a wedge if it is able to pass between the edge of the cover and the edge of the peripheral wall. Thus the labyrinth joint, by preventing penetration between the peripheral wall and the cover, prevents the canine tooth from gaining a mechanical advantage. 
     The bait within the station is protected from contact by a human finger or a dog&#39;s tongue by arrangement of a one or a plurality of openings which are distant from and baffled from the bait. The baffle is formed by an interior wall that extends from the peripheral wall between the opening and the bait, and the geometric relation between the location of the opening and the bait is such that a line passing perpendicular to a peripheral wall must be bent by at least about 180° before it can contact the bait. The interior wall extends substantially to the center of the bait station and supports the floor and cover from a crushing load caused in smaller stations by the closing jaw of a dog, or in larger stations by being stepped on by a person. 
     Reinforcements are provided to the base peripheral wall where it turns a corner in an area where a dog could get an effective grip on the corner and potentially crush the peripheral wall at the corner. The peripheral wall is reinforced by doubling it, i.e., by creating a second wall interior to the peripheral wall which is preferably reinforced with multiple radial webs which join the second interior wall to the outer peripheral wall. The second interior walls may be parallel to the outer peripheral wall or extend diagonally across the corners. 
     Features within the bait station lock a bait block within a restricted bait receptacle by peripheral walls and interior walls which surround the block on at least portions of all four sides, while leaving at least one point of access so the bait may be gnawed by the targeted rodent. Retention of the rodent bait block may additionally be achieved by disposing the bait block over a central post which prevents the bait block moving toward the rodent opening. In some cases such structure may remove the need to surround the bait block at least partially on four sides. 
     The plastic selected for formation of the base should be strong to prevent excessive deflections to the station structure, but also of a tough material which resists puncture or fracture. The cover is also constructed of strong tough material and may be made transparent or translucent to allow the status of the bait to be checked. Polypropylene or Nylons are examples of suitable materials for forming the bait station and the cover. 
     It is an object of the present invention to provide a bait station which resists being opened by children, dogs, other pets, domestic animals, and non-target wildlife. 
     It is a further object of the present invention to provide a pre-baited disposable bait station which better retains the enclosed bait. 
     It is another object of the present invention to provide a bait station which is resistant to a child accessing the bait through the rodent access openings. 
     It is yet another object of the present invention to provide a rodent bait station which provides for visual inspection of the enclosed rodenticide. 
     Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a mouse bait station of this invention. 
         FIG. 2  is an exploded perspective view of a rat bait station of this invention. 
         FIG. 3  is a top perspective view of the base of an alternative embodiment mouse bait station for use in a corner. 
         FIG. 4  is a top perspective view of the base of an alternative embodiment round mouse bait station. 
         FIG. 5  is a top perspective view of the base of an alternative embodiment two-opening mouse bait station. 
         FIG. 6  is a fragmentary cross-sectional side view of the lid and peripheral wall joint employed by the mouse bait station of  FIG. 1 . 
         FIG. 7  is a fragmentary cross-sectional side view of an alternative embodiment of a lid and peripheral wall joint such as can be used with the mouse bait stations of  FIGS. 3 and 4 . 
         FIG. 8  is a fragmentary cross-sectional side view of the lid and peripheral wall joint employed by the rat bait station of  FIG. 2 . 
         FIG. 9  is a fragmentary cross-sectional side view of a further alternative embodiment of a lid and peripheral wall joint such as can be used with a mouse bait station. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring more particularly to  FIGS. 1-9  wherein like numbers refer to similar parts, a bait station  20  for baiting mice is shown an  FIG. 1 . The mouse bait station  20  is comprised of a base  22 , and the lid  24 . The base  22  has a floor  26  surrounded by an upwardly extending peripheral wall  28 . The peripheral wall  28  defines an exterior surface  29 , an upper peripheral edge  30 , and together with the lid  24  defines an interior volume  31 . The base  22  is rectangular having two short sides  32  and two long sides  34 , with the result that the peripheral wall  28  and upper peripheral edge  30  have a corresponding rectangular shape. 
     The base  22  defines a bait receptacle  36  containing a rodenticide bait block  38 . The bait block  38  has the general shape of an extruded rectangular prism with additional gnaw edges provided by grooves in the faces of the bait block, such as the ones disclosed in U.S. Pat. No. 5,044,113, the disclosure of which is incorporated by reference herein. The bait receptacle  36  is positioned against a short wall  40  corresponding to one of the short sides  32  and extends partway along the two long walls  34  which join the short wall  40  at corners  44 . The short wall  40  and the corners  44  are reinforced with an interior wall  46  which is spaced inwardly of the short wall  40  and is connected by three short spacer segments  48  which extend to the short wall. Although for ease in manufacture only the central short spacer segments  48  may be used. 
     On either side of the interior wall  46  are reinforcing wall segments  50  which are inwardly spaced along the long walls  34  forming double walls resist penetration or deflection. The wall segments  50  are again connected by short spacer segments  52  which join the wall segments  50  to the exterior peripheral wall  28 . The bait receptacle  36  is completed by portions of an interior wall  54  which is partly cut away, leaving a knee wall  56  over which a rodent can gain access to the bait  38 . The close confinement of the bait block holds the bait block to limit damage to the bait block by the bait station being shaken, and prevents the movement of the bait out of the protected bait receptacle which holds the bait distant from the rodent access opening. 
     The base  22  has a floor plan which provides a path  58  to the bait  38  from a rodent access opening  60  in the peripheral wall  28 . The access opening  60  is strengthened by an inwardly protruding rim  61  that extends around the access opening adding rigidity to the peripheral wall  28  around the opening. The path  58  initial direction is nominally defined as being a line perpendicular to the portion of the peripheral wall  28  which defines the rodent access opening  60  and centered within the opening. The path  58  provides a circuitous route easily traversed by the target rodent, and defined by the peripheral wall  28  and the interior wall  54 . Referring to  FIG. 1 , immediately upon entry through the access opening  60  the rodent is blocked from moving to the right by the interior wall  54 , and blocked from moving straight ahead by an extension of the interior wall  62  which extends at a right angle from the main part of the interior wall  54 , such that the rodent and the rodent path is turned 90° to the left from the initial direction perpendicular to the peripheral wall. To reach the bait the rodent must proceed along the path  58  around the baffle formed by the wall portion  62  and must execute a turn of about 180° to access the bait  38  through the opening over the knee wall  56 . So if the rodent proceeds by making only 90° turns in approach the bait substantially three 90° turns are required to reach the bait. 
     Corners  64  opposite the corners  44  bracketing the bait receptacle  36  may also be reinforced by interior walls  66  which extend between the short side  32  and the adjacent long sides  34 . The corners  64  have perpendicular flanges  68  which extend upward from the floor  26  along the wall  28  and a short distance inwardly from the apex of the corners along radiuses defining the corners. The perpendicular flanges  68  support the lid  24  overlying the corners  64 . 
     As the bait station is not intended to be rebaited, the lid  24  is preferably locked to the base without any provision for opening the lid. The bait station is prebaited and the lid secured to the base by the manufacturer before distribution to retail outlets. The lid  24  of the bait station  20  is constructed of translucent or clear plastic so that the bait  38  is visible and it can be determined whether the bait has been visited by rodents. The lid has five prongs  70 ,  86  which latch within receptacles  72 ,  88  which are integrally formed with the base  22 . Each prong extends downwardly from the inner cover surface  74  of the lid  22  and terminates with a hook  76 , as shown for example in  FIG. 6 . As shown in  FIG. 1 , the receptacles  72 ,  88  have rectangular openings  78  which face upwardly. As shown in  FIG. 6 , the receptacles have hook deflexing flanges  80  which have upper surface  81  which force the hook on each prong into the opening of a receptacle  72 ,  88 . Each receptacle has a hook opening  82  below the deflection flange  80  which extends downwardly and which faces the interior of the station  20 . The prong  70  and hook  76  pass through the rectangular opening  78  until the hook  76  is opposite an opening  82 , where the prong  70  elastically moves the hook  76  into position below the deflection flange  80 , thereby locking the hook in engagement with a lower surface  84  of the flange  80 . 
     The central prong  86  joins a central receptacle  88  which is integrally joined with the inner wall  54  and which not only locks the center  90  of the lid  24  to the base  22  but the receptacle also supports the center of the lid against crushing forces. A bar structure  91  extends downwardly from the inside  74  of the cover across the bait receptacle  36  and toward the bait  38  to further constrain bait movement within the bait receptacle. 
     The receptacles  72  perform a double function with respect to the bait receptacle  36  in forming an extension to the reinforcing wall segments  50 . The formation of the four receptacles  72  which are positioned against the peripheral wall  28  using the injection molding process requires that the mold cavity have pillars positioned beneath the receptacles  72  so that the mold pillars form pillar indentations  73  on the outside  29  of the peripheral wall  28 . The pillar indentations  73  ordinarily require only a tapered cross-section which leads to the receptacle structure  72 . However, in order to create an exterior surface  29  which minimizes tooth gripping surfaces, the pillars have tapered sides which create pillar indentations  73  with gently angled sides  75  as shown in  FIG. 1 . 
     As shown in  FIG. 6 , a labyrinth joint  92  is formed between the peripheral edge  94  of the lid  24  and the uppermost peripheral edge  30  of the base  22 . The labyrinth joint  92  is shown in  FIG. 6  as slightly spaced apart for clarity. The peripheral edge  94  of the lid  24  starts from the upper surface  96  which transitions into a gentle downward radius  98  which forms the peripheral edge  94 . The lid  24  has portions  100  which step inwardly, and portions which step downwardly  102  and form a lowermost edge  103 . The downward step facing outwardly formed by the lid portions  100 ,  102  lines up with a complementary step on the base upper peripheral edge  30  which has portions  104  which step inwardly, and portions  106  which step downwardly and portions  108  which step inwardly again, to form a downward step facing inwardly and upward. The result is the joint  92  forming a labyrinth path which is highly resistant to a canine tooth, fingernail or other object passing between the lid  24  and the base  22  and obtaining a grip adequate to pry the lid away from the base. Little peripheral edge  30  protrudes beyond the lid  24 , such that it is difficult to obtain any grip on the lid or the base such that they can be separated. 
     The portion of the interior volume  31  occupied by the rodent in gaining access to the bait  38  is preferably sufficient such that the rodent can turn around and exit the bait station opening  60 , nose first, as it is generally understood that rodents are more willing to access spaces which allow them to emerge nose first. While the precise dimensions are not critical, by way of example the bait station  20  may be 3½ inches long by 2½ inches wide by 1¼ inches high, and the corners  44 ,  64  have a radius of ½ inch. The labyrinth joint  92  and the integral connection between the floor  26  of the base and the peripheral wall  28  have a radius of curvature of about ¼ inches. Double walls mean that even if a chewing pet can puncture the outer wall, the spacing of the inner wall away from the outer wall makes it difficult to penetrate both walls. The gentle radii of the lid and the base also make it difficult for pets to effectively get a grip on these areas and chew on them. 
     A bait station  120  for rats is shown in  FIG. 2  which employs many of the design features discussed with respect to the mouse bait station  20 . The bait station  120  is composed of a base  122  and a lid  124 . The base  122  has a floor  126  and an upwardly extending peripheral wall  128  terminating in an upper peripheral edge  130 . The base  122  and the lid  124  define therebetween an internal volume  131 . The base again has a generally rectangular shape with two short walls  132 ,  133  and two long walls  134 ,  135 . One short wall  132  is substantially straight, and the other short wall  133  forms a gentle curve in the shape of an arc of a circle. An interior wall  138  extends from the straight short wall  132  substantially parallel to the long walls, approximately 60% of the distance between the short straight wall  132  and the curved wall  133 . The interior wall  138  divides the short straight wall  132  approximately in half, forming a first wall portion  140  which defines an opening  142  for the entry of a rat into the interior  131 , and a second slightly smaller wall portion  144  which forms part of a bait receptacle  146 . The access opening  142  is strengthened by an inwardly protruding rim  161  that extends around the access opening adding rigidity to the peripheral wall  128  around the opening. 
     The bait receptacle  146  is formed between the second wall portion  144  of the short wall  132 , and a portion  148  of the interior wall  138 , and a portion  150  of the bait side long side wall  135 . Finally, an extension  152  of the interior wall  138  extends between the interior wall  138  and joins the long wall  135  forming the bait receptacle  146 . A bait post  156  extends upwardly from the floor  126  and is approximately centered within the bait receptacle  146 . A bait block (not shown) having a central hole is placed over the post  156 . Portions of the extension  152  of the interior wall form a knee wall  154  over which a rodent can gain access to a bait block within the bait receptacle  146 . The bait receptacle  146  is reinforced along the corner  157  by reinforcing wall  160  which extends from the second wall portion  144  to the wall portion  150  of the bait station base. The reinforcing wall  160  forms a corner  162  which positions and holds the bait block (not shown). In general, corners near the bait block, and forming part of the bait receptacle which are relatively sharp (for example having an interior angle of less than about 135°, typically about 90° as shown in  FIGS. 2 and 3 ), will be reinforced by a further interior wall  66 ,  160  substantially the height of the peripheral wall and spaced inwardly of the peripheral wall at said corner. The reinforcing wall segment is wholly or substantially interior to the bait receptacle and extending across the corner with the included angle of less than 135° from the outer peripheral wall to the outer peripheral wall to create a reinforced corner. 
     The base  122  has a floor plan which provides a path  158  to the bait from the rat access opening  142 . The path  158  again defines a direction perpendicular to the straight short wall  132  which defines the rodent access opening  142  and is centered within the opening. The path  164  provides a circuitous route easily traversed by the target rodent, and defined by the peripheral wall  128  and the interior wall  138 . Referring to  FIG. 2 , immediately upon entry through the access opening  142  the rat is blocked from moving to the left by the interior wall  138 , and moves straight ahead until it must make a 180° turn around the end  166  of the interior wall  138  to access the bait through the opening over the knee wall  154 . A portion  168  of the interior wall near the wall end  166  is angled to narrow the path  158  just before the path passes around the interior wall  138  and turns toward the bait (not shown) in the bait receptacle  146 . This narrowing of the path  158 , combined with the 180° turn and the spacing of the bait from the curved wall  133  prevents a small child from reaching through the access opening  60  and reaching around the interior wall  138  to reach the bait in the bait receptacle  146 . The bait station  120  is designed with interior walls shielding the bait from the rodent accessible opening so that if the rodent proceeds by 90° turns, two 90° turns must be made to reach the bait, thus effectively isolating the bait from the rodent access opening, which isolates the bait from pets and humans. 
     The lid  24  of the bait station  120  is constructed of translucent or clear plastic so that the bait in the bait receptacle  146  is visible and it can be determined whether the bait has been visited by rodents. The lid has a lower surface  169 , an upper surface  171 , a peripheral edge  175  and seven prongs descending from the inner surface of the lid. The seven prongs consist of six peripheral prongs  170  which latch within receptacles  172 , and one central prong  182  which latch within a central protrusion receptacle  184  which extends up from the base. All the receptacles  172 ,  184  are integrally formed with the base  122 . Each prong extends downwardly from the inner cover  174  of the lid  122  and terminates with a hook  176 . 
     The receptacles  172 ,  184 , have upwardly facing rectangular openings  178  with a hook deflexing flange  180  which has an upper surface  181  which forces the hook on each prong into the opening of a receptacle  172 ,  184 . The prongs  170  and the respective hooks  176  pass through the openings  178  and are elastically moved to engage the bottoms  183  of the flanges  180  in a way similar to that described with respect to the arrangement shown in  FIG. 6 . The central prong  182  joins the central protruding receptacle  184  which is integral to the inner wall  138  and which not only locks the center  185  of the lid  124  to the base  122  but the receptacle also supports the center of the lid against crushing forces, such as produced by stepping on the lid  124 . Because the bait station  120  is injection molded, the thickness and therefore the amount of material used in the interior wall  138  can be minimized by extending the wall only part way to the lid  124 , and having the interior wall completed by a first short wall segment  187  which extends downwardly and slightly overlaps the interior wall on the side away from the bait receptacle  146  between the straight wall  132 , and the central protruding receptacle  184 , and a second short wall segment  189  which extends downwardly and slightly overlaps the angled portion  168  of the interior wall  138 , on the bait receptacle side. The lid  124  has two additional short wall segments  191  which in combination with the first short wall segment  187  serve to hold a bait block (not shown) in the bait receptacle  146 . 
     The formation of the six receptacles  172  which are positioned against the peripheral wall  128  using the injection molding process requires that the mold cavity have pillars positioned beneath the receptacle  172  so that the mold pillars form pillar indentations  177  on the outside  129  of the peripheral wall  128 . The pillar indentations  177  have the necessary tapered cross-section which leads to the receptacle structure  172 . However, in order to minimize tooth gripping surfaces, the pillars have tapered sides  173  which create pillar indentations similar to those shown in  FIG. 1  with gently angled sides. 
     The upper peripheral edge  130  of the base  122  meets the peripheral edge  175  of the lid  124  in a labyrinth joint  186  as shown in  FIG. 8 . The peripheral edge  175  of the lid  124  starts from the upper surface  171  which transitions into a gentle downward radius  188  which forms the peripheral edge  175 . The edge  175  has a simple flat lower surface  192  which fits with a complementary downward step facing inwardly  194  in the upper peripheral edge  130  which step has portions  196  which step downwardly and portions  190  which step inwardly. The result is that the joint  186  forms a labyrinth path which again is highly resistant to a canine tooth, finger nail or other object passing between the lid  124  and the base  122  so as to pry the lid away from the base. 
     The portion of the interior volume  131  occupied by a rat in gaining access to the bait is preferably sufficient such that the rat can turn around and exit the bait station opening  142  nose first, as it is generally understood that rodents are more willing to access spaces which allow them to emerge nose first. The bait station  120  as shown in  FIG. 2  may have, for example, dimensions of 7½ inches long, 5¼ inches wide, and 3 inches high. The labyrinth joint  186  and the integral connection between the floor  26  of the base and the peripheral wall  28  have a radius of curvature of about ¼ inches. 
     There are general design principles of this invention which can be used to form a variety of bait stations: reinforce corners and sides positioned about a bait receptacle; avoid sharp corners, which facilitate gnawing; permanently attach lids to the bait station bases by resilient members which lock the covers to the bases; employ serpentine paths between the rodent entry to the bait station, and the bait; securely retain bait blocks; centrally attach the cover to the base; and facilitate interior bait observations with a transparent cover. Three additional configurations for applying these design principles are illustrated in  FIGS. 3-5 , with the bait station covers removed for clarity. 
       FIG. 3  shows a pentagonal bait station base  222  designed to fit in a corner. The base  222  has an opening  224  in a peripheral wall  228  and a bait receptacle  238  which surrounds a bait block (not shown) on part of at least four sides, wherein the bait receptacle is double walled where the bait receptacle joins the peripheral wall  228 . A lid (not shown) is joined to five receptacles  272  and a central receptacle  284  in a manner similar to that shown with respect to the bait station  20 . A path  258  provides a circuitous route easily traversed by the target rodent, and defined by the peripheral wall  228  and the interior wall  254  which involves turns of over 180°. 
       FIG. 4  shows a circular bait station base  322 . The base  322  has an opening  324  in a peripheral wall  328  and a bait receptacle  338  which surrounds a bait block (not shown) on part of at least four sides, wherein the bait receptacle is double walled where the bait receptacle joins the peripheral wall  328 . A lid (not shown) is joined to five receptacles  372  and a central receptacle  384  in a manner similar to that shown with respect to the bait station  20 . A path  358  provides a circuitous route easily traversed by the target rodent, and defined by the peripheral wall  328  and the interior wall  354  which involves turns of over 180°. 
       FIG. 5  shows a two-entry rectangular bait station base  422  design. The base  422  has two openings  424  in a peripheral wall  428  and bait receptacle  438  which surround a bait block (not shown) on part of at least four sides, wherein the bait receptacle is double walled where the bait receptacle joins the peripheral wall  428 . A lid (not shown) is joined by hooked prongs to six receptacles  472 , and a central receptacle  484  in a manner similar to that shown with respect to the bait station  20 . A path  458  provides a circuitous route easily traversed by the target rodent, and defined by the peripheral wall  428  and the interior wall  454  which involves turns of over 180°. 
     It should be understood that where  FIGS. 3-5  depict mouse scaled devices, similar devices for use with rats based on the principles illustrated with respect to  FIG. 2  may also be used, e.g., a larger scale device which utilizes the interior wall to prevent a child&#39;s arm from reaching into the bait receptacle. 
     A further design of a labyrinth joint between a lower peripheral edge  521  of a bait station lid  524  and an upper peripheral edge  530  of the peripheral wall  528  is shown in  FIG. 7 . The peripheral wall  528  has an inward facing step  532  into which the lower peripheral edge  521  of the lid  524  fits. A yet further labyrinth joint is illustrated in  FIG. 9  between a bait stations lid  624 , and an upper peripheral edge  630  of a peripheral wall  628 . The labyrinth joint is similar to that shown in  FIG. 7  with the addition of a portion  632  of the lid  624  which extends and overlies a portion  634  of the peripheral wall  628 , so the portion  632  of the peripheral wall  530  steps in, further portions  636  step down and finally a portion  638  of the peripheral wall steps in again in contact with corresponding surfaces on the lid  624 . 
     It should be understood that a bait block referrers generally to a single unitary generally but not necessarily prismatic in shape block which contains rodenticide, rodent feed, and a binder (e.g., paraffin wax), and is distinct from rodenticide impregnated grain, or pellets formed of the same or similar rodenticide, feed, and binder. As used herein bait block referrers to one or more items of bait which can be secured within a bait receptacle which provides a sufficiently large access opening that the targeted rodent can gain access to the rodenticide within the bait receptacle. 
     It should be understood that where lid prongs with hooked ends are shown, other arrangements of structures which depend downwardly from the lid and which lock the lid to receptacles in the base of the bait station could be used. 
     It should be understood that where the floor  26 ,  126  is described and claimed as completely surrounded by the peripheral wall  28 ,  128  the wall may define one or more rodent openings, which do not completely break the wall, rather they leave a continuous upper peripheral edge  30 ,  130 . 
     It should be understood that the reinforcing interior wall segments  50 ,  66 ,  160  which create double walls and reinforced corners which form part of the bait receptacle  36 ,  136 , extend upwardly from the floor  26 ,  126  of the bait stations and extend substantially the height of the peripheral wall  28 ,  128 . The interior wall segments are integrally formed as part of the base molding. 
     It should be understood, moreover, that the peripheral walls of the bait stations extend from the base floor to support the bait station cover. The interior walls are formed either wholly integral with the base or extend from the base and the cover, typically mostly from the base. 
     In general the bait station is designed with interior walls shielding the bait from the rodent accessible opening so that if the rodent proceeds by 90° turns at least two or three 90° turns must be made to reach the bait, thus effectively isolating the bait from the rodent access opening. 
     The center  90 ,  185  of the lid  24 ,  124  is defined as the center point which is most distant from all points on peripheral edge  94 ,  175  of the lid, and practically within a region closer to the center point than the peripheral edge. 
     It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.