Abstract:
A litter box having apparatus for catching and returning litter being tracked from the litter box, and a method of assembling the litter box. The litter box includes a container for containing litter. An opening and a litter return window are formed in the container. Stair steps defining slots therebetween extend from the opening. A litter return slide is disposed beneath the slots and slopes downward towards the litter return window. As the animal traverses the stair steps, litter adhering to the paws of the animal is dislodged and falls through the slots to be caught by the litter return slide. The dislodged litter travels down the litter return slide and through the litter return window so as to return the dislodged litter to the litter container. Thus, the animal is prevented from tracking litter beyond the litter box, so that litter cleanup is reduced and sanitation is enhanced.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to pet litter boxes, and more particularly relates to pet litter boxes intended to reduce escape of litter therefrom. 
     BACKGROUND OF THE INVENTION 
     A litter tray or litter box having litter therein is typically used by a pet cat, rabbit or other small pet animal for indoor collection of feces and urine. The litter material commonly used includes granulated moisture absorbing clay that includes aluminum silicates and/or other minerals. Other materials are also used as litter, such as wood chips, pelletized paper, pelletized grain, pelletized corncobs, and pelletized wheat straw grasses. 
     More specifically, the litter can be a “non-clumping” litter comprising sand or a mixture of zeolite, diatomite, and sepiolite. However, when removing animal waste from the litter box in which non-clumping litter was used, the entire contents of the litter box must be emptied. Alternatively, “clumping” litter may be used rather than non-clumping litter. Clumping litter, which can include bentonite clay (absorbent aluminum phyllosilicate) or diatomaceous earth, forms a relatively solid mass when wet. The solid mass can then be scooped from the litter box without emptying the entire contents of the litter box. 
     Some animals, such as cats, have a natural instinct to bury their waste in loose soil when the animal is in the wild. A litter box relies on this natural instinct to accomplish its function of collecting the animal&#39;s waste. In this regard, the litter box is filled with about one inch (2.5 centimeters) of the litter for simulating loose soil, so that the animal will instinctively bury its waste in the litter. However, it has been observed that the granulated or pelletized litter will often, at least temporarily, adhere to the animal&#39;s paws regardless of the composition of the litter, and regardless of whether the litter is non-clumping litter or clumping litter. When this occurs, the animal will then “track” the litter onto nearby surfaces as the animal exits the litter box. 
     In addition, about 80% of litter purchased by pet owners is the previously mentioned clumping litter rather than the non-clumping litter. However, clumping litter has a smaller average grain size and is lighter than non-clumping litter. In this regard, the litter grain size of the clumping litter may vary between approximately 0.019685 inch (0.5 millimeter) and approximately 0.059055 inch (1.5 millimeter). Therefore, there is a greater likelihood that the clumping litter typically used will be tracked, expelled, or otherwise scattered more easily from the litter box as the animal buries its waste in the litter. 
     Also, the litter tracked, expelled, and otherwise scattered by the animal onto nearby surfaces may be inadvertently tracked even further away from the vicinity of the litter box by humans walking or moving through an area near the litter box. 
     The litter escaping the litter box due to the cat&#39;s paws tracking, expelling, or otherwise scattering the litter outside the litter box, and due to people walking near the litter box, results in time spent subsequently vacuuming, sweeping, and/or even mopping an area where the litter has escaped from the litter box. In addition, litter escaping the litter box might stain furniture fabric, carpeting, and other items located near the litter box. Moreover, the litter escaping the litter box and transferred to nearby surfaces creates an unsanitary indoor environment. This is so because the tracked and scattered litter may be contaminated with bacteria (e.g.,  escherichia coli ) and protozoa (e.g.,  toxoplasma gondil ) that can cause or exacerbate health issues in some people. Therefore, for all the forgoing reasons, it is desirable to prevent inadvertent escape of litter from the litter box. 
     Prior art approaches have been taken to prevent inadvertent escape of litter from a litter box. For example, an apparatus for preventing litter from being scattered upon the floor outside of a litter box and beyond, whether strewn by a cat during or after using the litter box, or by the owner when cleaning the litter box is disclosed in the prior art. In this regard, an enclosure is provided having a front side, a left side, a right side and a base. The device is designed to encourage the cat to step out of the litter box and into a tracked litter receptacle for collecting tracked litter. The device is further designed to corral not only litter tracked onto the bottom of the cat&#39;s paws, but litter tossed, flipped and spilled out of the litter box. However, use of this device appears to create at least two separate areas requiring cleanup. The two separate areas being the initial site where the litter is contained, and an additional site where the litter has been subsequently corralled. Cleaning two separate areas of tracked litter rather than a single area is time consuming and, hence, inconvenient. 
     Another known approach provides a sanitary cat path for use with a litter box, or a cat door, the sanitary cat path including an elevated apertured walkway operating to remove the litter or debris from the paws of the cat so that the litter or debris will not be deposited on the floor, and/or tracked about the home and, preferably, providing a tray for capturing the litter or debris and easily disposing of it. However, use of this device also creates at least two separate areas requiring cleanup, the two separate areas being the initial site where the litter is located, and the additional site where the tracked litter is subsequently captured by the tray. Cleaning two separate areas of tracked litter rather than a single area is time consuming and, consequently, inconvenient. In addition, this reference appears merely to disclose a tray useable with a conventional litter box, rather than a fully configured litter box construction that includes a tray. 
     Yet another known approach provides a louvered ramp that serves as a cat&#39;s paw-cleaning entry and exit ramp ascending to, and descending from, a cat litter box. However, this reference appears merely to disclose a louvered ramp useable with a conventional litter box. 
     SUMMARY OF THE INVENTION 
     A litter box having apparatus for reducing the tracking of litter beyond the litter box includes a container having a base and a cover that covers the base. A quantity of litter is contained in the base, the litter being for receiving animal waste, such as from a pet cat. In addition, a litter return window is formed in the base for purposes disclosed herein below. An opening formed in the cover allows the cat to move into and out of the container. 
     After using the litter, the cat typically has granulated particles of litter adhering to the bottom of its paws. To prevent transfer of the litter from the cat&#39;s paws to surfaces external to the container, such as furniture and floors, a litter removal pathway is coupled to the container. The pathway extends outwardly from the opening defined by the cover, and is configured to remove the litter from the paws of the cat. The pathway includes a plurality of stair steps defining slots therebetween, the slots extending through the pathway. As the cat traverses the plurality of stair steps, most of the litter adhering to the paws of the cat is removed by the stair steps, and falls downward through the slots. A downwardly sloping litter return guide, chute, or slide is disposed beneath the pathway and spans the slots. An end portion of the downwardly sloping litter return slide passes through the previously mentioned litter return window formed in the base. Thus, litter falling from the cat&#39;s paws and through the slots is caught by the litter return slide. Thereafter, the litter slidably travels downwardly along the litter return slide, so that the litter passes through the litter return window, and is returned to the base of the container to rejoin the litter contained within the base. 
     A pair of barriers may be coupled along sides of the pathway for guiding the cat along the pathway. In this manner, the cat remains on the pathway rather than prematurely jumping off a side of the pathway prior to sufficient transfer of litter from the cat&#39;s paws. In addition, a removable mesh or grate covering a top portion of the pathway can be provided for enhancing comfort of the cat as the cat traverses the pathway. Moreover, an obstruction can be removably coupled to the container and located at the opening for slowing exit of the animal through the opening. For example, a removable brush assembly may be provided near the opening formed in the cover for allowing the cat to rub against the brush as the cat exits the opening. The cat will instinctively linger or pause at the opening so as to rub itself against the brush. Pausing to rub itself against the brush will cause the cat to remain longer on the pathway for allowing more time for the litter to be dislodged from the cat&#39;s paws and to fall through the slots. 
     Further, a support structure is provided that serves a dual purpose. In this regard, the support structure is disposed beneath and is coupled to the pathway for supporting the pathway. In addition, the support structure substantially surrounds the litter return slide, but is spaced-apart from the litter return slide for defining a storage compartment between the litter return guide and the support structure. Thus the support structure simultaneously supports the pathway and defines a storage compartment between the litter return guide and the support structure. If desired, cleaning materials and/or litter bags may be conveniently stored in the compartment. The cleaning materials are used for cleaning the slide, base, and remainder of the container when desired and the litter bags are used for disposal of soiled litter. 
     Thus, the apparatus removes tracked litter from the bottom of the cat&#39;s paws and returns the tracked litter to the litter contained in the base of the container. In this manner, the apparatus prevents transfer, spillage, scattering and tracking of the cat litter onto nearby surfaces, such as furniture and floors. Preventing transfer, spillage, scattering, and tracking of the cat litter onto such surfaces and automatically returning the tracked litter to the litter contained in the litter container avoids time needed to clean escaped litter from the nearby surfaces. In addition, preventing transfer, spillage, scattering, and tracking of the cat litter from the container enhances sanitation by reducing likelihood of contamination of nearby surfaces by bacteria and protozoa that could pose a health hazard to people. 
     A first general aspect of the invention is a litter box having apparatus for catching and returning tracked litter, the litter box including: a container for containing litter, the container defining an opening for allowing exit of an animal, and the container defining a litter return window for allowing return of tracked litter to the container; a pathway extending from the opening for enabling travel of the animal therealong after exiting the opening, the animal tracking the litter along the pathway after exiting the container, the pathway having at least one slot therethrough for passage of the tracked litter down through the at least one slot; and a litter return slide disposed beneath the pathway and through the litter return window, the litter return slide being for catching the tracked litter passing down through the at least one slot, and then for slidably returning the tracked litter through the litter return window and into the container. 
     In some embodiments, the litter box further includes a barrier coupled to the pathway for blocking exit of the animal from the pathway. 
     In some embodiments, the pathway includes a grate for enhancing support of the animal while the animal travels along the pathway. In further embodiments, the grate is removable. 
     In some embodiments, the litter box further includes a brush cooperative with the opening defined by the container so as to allow the animal to rub against the brush while the animal exits the opening. 
     In some embodiments, the litter box further includes a support structure coupled to the pathway for supporting the pathway. In further embodiments, the support structure substantially surrounds the litter return slide, the support structure and the litter return slide together defining a storage compartment therebetween. In still further embodiments, the support structure includes an access door for allowing access to the compartment. 
     In some embodiments, the pathway includes a plurality of stair steps. 
     In some embodiments, the litter box further includes an obstruction removably coupled to the container and disposed at the opening for slowing exit of the animal through the opening. 
     Another general aspect of the invention is a litter box having apparatus for catching and returning tracked litter, the litter box including: a container having a base for containing the litter and a cover for covering the base, the cover defining an opening for allowing exit of an animal tracking the litter from the base, the base defining a litter return window for allowing return into the base of tracked litter through the litter return window; a plurality of stair steps defining an inclined pathway extending from the opening for travel therealong of the animal exiting the opening, adjacent pairs of stair steps each defining a slot therebetween for passage of the tracked litter down through the slot; and a litter return slide disposed beneath the plurality of stair steps for catching the tracked litter passing through each slot therein, the litter return slide downwardly extending from the plurality of stair steps and through the litter return window, tracked litter passing through the slot while the animal tracks the litter from the base, the litter return slide catching the tracked litter after the tracked litter passes through each slot, whereafter the tracked litter slides along the litter return slide and through the litter return window and back into the base. 
     In some embodiments, the litter box further includes a pair of oppositely disposed barriers coupled to the pathway for blocking exit of the animal from the pathway. 
     In some embodiments, the pathway includes a rubberized grate for enhancing comfort of the animal while the animal travels along the pathway and across the grate. In further embodiments, the grate is removable from the pathway. 
     In some embodiments, the litter box further includes a rubberized brush coupled to the cover and cooperative with the opening defined by the cover for allowing the animal to rub against the brush while the animal exits the opening. 
     In some embodiments, the litter box further includes a support structure coupled to the plurality of stair steps for supporting the plurality of stair steps. In further embodiments, the support structure substantially surrounds the litter return slide, the support structure and the litter return slide together defining a storage compartment therebetween. In still further embodiments, the support structure includes an access door in communication with the compartment for allowing access to the compartment. 
     In some embodiments, the litter box further includes an obstruction removably coupled to the container and disposed at the opening for slowing exit of the animal through the opening. 
     Another general aspect of the invention is a method of assembling a litter box having apparatus for catching and returning tracked litter. The method includes: providing a container for containing the litter, the container defining an opening for allowing exit of an animal tracking litter from the container and defining a litter return window for allowing return of the tracked litter to the container; extending a pathway from the opening for travel therealong of the animal exiting the opening, the animal tracking the litter from the container and along the pathway, the pathway defining at least one slot therethrough for passage of the tracked litter through the at least one slot; and disposing a litter return slide beneath the at least one slot and through the litter return window, the litter return slide being for catching the tracked litter passing through the at least one slot, and being for slidably returning the tracked litter through the litter return window and into the container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more fully understood by reference to the detailed description in conjunction with the following figures, wherein: 
         FIG. 1  is a view in perspective of a first embodiment of the litter box with apparatus for catching and returning litter being tracked therefrom by an animal, such as a cat; 
         FIG. 2  is a view in elevation of the embodiment of  FIG. 1 ; 
         FIG. 3  is a view in vertical section of the embodiment of  FIG. 1 ; 
         FIG. 4  is an exploded view in vertical section of the embodiment of  FIG. 1 ; 
         FIG. 5  is a fragmentary view in vertical section of a pathway belonging to the embodiment of  FIG. 1 , the pathway including a plurality of stair steps; 
         FIG. 6  is a view in perspective of a second embodiment of the litter box having apparatus for catching and returning litter being tracked therefrom; 
         FIG. 7  is a view in perspective of a third embodiment of the litter box having apparatus for catching and returning litter being tracked therefrom; 
         FIG. 8  is a view in elevation of a fourth embodiment of the litter box having apparatus for catching and returning litter being tracked therefrom; 
         FIG. 9  is a view in perspective of a fifth embodiment of the litter box having apparatus for catching and returning litter being tracked therefrom; 
         FIG. 10  is a view in vertical section of the embodiment of  FIG. 9 ; and 
         FIG. 11  is a flowchart of an illustrative method of assembling a litter box having apparatus for catching and returning litter being tracked therefrom. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 ,  2  and  3 , there is shown a first embodiment apparatus, generally referred to as  10 , for catching and returning litter being tracked therefrom. First embodiment apparatus  10  includes a container, generally referred to as  20 , having a generally parallelpiped-shaped base  30 . The base  30  includes a horizontal floor  40 , an upright rear base panel  50  integrally formed with floor  40 , and an upright front base panel  60  disposed opposite rear base panel  50  and integrally formed with floor  40 . Front base panel  60  defines a litter return window  70  therein for reasons disclosed hereinbelow. Base  30  further includes an upright first base side panel  80  integrally formed with floor  40 , rear base panel  50  and front base panel  60 . In addition, container  20  includes an upright second base side panel  90  disposed opposite first base side panel  80  and integrally formed with floor  40 , rear base panel  50  and front base panel  60 . An upper perimeter of base  30  may define a recess  93  therearound for reasons disclosed hereinbelow. This configuration of base  30  defines an open lower volume  95  in container  20  that holds litter  100  therein. Litter  100 , which is disposed on floor  40 , may include a granulated non-clumping litter material, such as sand or a mixture of zeolite, diatomite and sepiolite. Alternatively, litter  100  may include a granulated clumping litter material, such as bentonite clay (absorbent aluminum phyllosilicate) or diatomaceous earth. A purpose of litter  100  is to receive and absorb fecal matter and urine deposited therein by a pet animal, such as a cat  110  possessing feet or paws  115 . 
     Referring again to  FIGS. 1 ,  2  and  3 , container  20  also has a generally parallelpiped-shaped cover  120  sized to be mounted on base  30  for covering base  30 . Cover  120  includes a ceiling or top panel  130 , a generally vertical rear cover panel  140  integrally formed with top panel  130 , and a generally vertical front cover panel  150  disposed opposite rear cover panel  140  and integrally formed with top panel  130 . Front cover panel  150  defines an opening  155  therein for ingress and egress of cat  110  respectively into and out of container  20 . Cover  120  further includes a vertical first cover side panel  160  integrally formed with top panel  130 , rear cover panel  140 , and front cover panel  150 . In addition, container  20  includes a generally vertical second cover side panel  170  disposed opposite first cover side panel  160  and integrally formed with top panel  130 , rear cover panel  140  and front cover panel  150 . This configuration of cover  120  defines an open upper volume  175  in container  20 . A handle  180  may be connected to top panel  130  for lifting cover  120  from base  30  and for lowering cover  120  onto base  30 . When cover  120  is lowered onto base  30 , a lower perimeter of cover  120  will be received in recess  93  defined by the upper perimeter of base  30  in order to releasibly secure cover  120  to base  30 . In addition, a brush assembly, generally referred to as  190 , including a plurality of rubberized bristles  195  may be connected to cover  120  at a location near opening  155  for reasons disclosed hereinbelow. Brush assembly  190  is connected to cover  120  by removable fastener means, such as by a suitable adhesive (not shown) or at least one screw  197 . As another example, brush assembly  190  may be connected to cover  120  by means of a pressure latch (not shown), clip (also not shown) or other suitable removable fastener means. In this manner, if not needed, brush assembly  190  can be removed by removal of screw  197 , the pressure latch, the clip or the other means used to connect brush assembly  190  to cover  120 . Container  20  may be made from any suitable light-weight material, so that container  20  is portable and manually locatable in any convenient location. In this regard, container  20  may be a light-weight metal, such as thin gauge aluminum, or a suitable durable light-weight plastic material, such as acrylonitrile-butadiene styrene. 
     As previously mentioned, it has been observed that, after cat  110  uses litter  100 , particles of granulated or pelletized litter from litter  100  may, at least temporarily, adhere to the cat&#39;s paws  115 . When this occurs, cat  110  will then track the litter onto nearby surfaces as cat  110  exits container  20 . It is desirable to prevent cat  110  from tracking the litter onto nearby surfaces to avoid time consuming cleanup and to reduce risk of contaminating the nearby surfaces with disease causing bacteria and protozoa. 
     Therefore, referring to  FIGS. 1 ,  2 ,  3 ,  4  and  5 , an inclined walkway or pathway, generally referred to as  200 , that removes or dislodges tracked litter from paws  115  of cat  110  is provided. Pathway  200  upwardly outwardly extends from opening  155  and includes a plurality of ascending stair steps  210  arranged parallel one to another. At least some of stair steps  210  may be rubber or similar material for allowing cat  110  to comfortably travel or traverse along pathway  200 . By way of example only, and not by way of limitation, there may be five stair steps  210 . Alternatively, there may be more or fewer than five stair steps  210 , if desired. However, it may be appreciated that the greater the number of stair steps, the greater the likelihood that all tracked litter will be removed from paws  115  of cat  110 . In addition, although pathway  200  is described herein as being upwardly inclined or ascending, it may be understood, based on applicant&#39;s teachings herein, that pathway  200  may be level or downwardly sloping or descending, if desired. Moreover, stair steps  210  may successively increase in length to progressively widen pathway  200  as pathway  200  extends from opening  155 , if desired. Stair steps  210  are spaced-apart, so that adjacent ones of stair steps  210  each define a slot  220  therebetween for reasons provided hereinbelow. 
     Referring again to  FIGS. 1 ,  2 ,  3 ,  4  and  5 , a surface  230  of each stair step  210  may be textured for facilitating removal of tracked litter from paws  115  of cat  110 . Surface  230  may be textured by means of a multiplicity of raised bumps or nodules  235 , or other suitable texturing. Moreover, surface  230  of each stair-step  210  may be curved or convex, as shown, so that tracked litter more easily falls away from stair step  210 . In this manner, likelihood of tracked litter re-adhering to paws  115  as the cat  110  travels pathway  200  is reduced. In addition, presence of previously mentioned brush assembly  190 , which forms an obstruction at opening  155 , allows cat  110  to rub against bristles  195  as cat  110  exits opening  155  of container  20  and initiates travel along pathway  200 . It has been observed that cat  110  will tend to instinctively linger at opening  155  and delay travel along pathway  200  while cat  110  rubs against bristles  195 . This is beneficial because the longer cat  110  remains on pathway  200 , the greater the likelihood that tracked litter will be dislodged from paws  115 . 
     Referring again to  FIGS. 1 ,  2 ,  3 ,  4  and  5 , first embodiment apparatus  10  further includes a support structure, generally referred to as  240 , coupled to pathway  200  for supporting pathway  200 . Material comprising support structure  240  may be thin gauge aluminum, or a suitable durable plastic material, such as acrylonitrile-butadiene styrene. Support structure  240  includes three upright side walls, such as left sidewall  250   a , center sidewall  250   b  and right sidewall  250   c . Left side wall  250   a  and right side wall  250   c  are connected to center side wall  250   b , such as by means of a suitable epoxy adhesive (not shown) or at least one screw fastener  255 . Side walls  250   a/b/c  are perpendicularly disposed and integrally connected to each other. Side walls  250   a/b/c  are also integrally connected to a floor  260 , such as by means of a suitable epoxy adhesive or at least one screw fastener  255 . Hence, one side of support structure  240  is not bounded by a side wall. In this manner, side walls  250   a/b/c  and floor  260  define an open volume  270  in support structure  240 . 
     Still referring to  FIGS. 1 ,  2 ,  3 ,  4  and  5 , support structure  240  is coupled to front base panel  60 , such as being positioned sufficiently adjacent to front base panel  60 , so that open volume  270  is in communication with litter return window  70 , as shown. Each of opposing side walls  250   a  and  250   c  define a plurality of spaced-apart cutouts  280  along a upper edge of each side wall  250   a  and  250   c  for receiving opposing ends of respective ones of the plurality of stair steps  210 . In this manner, each of stair steps  210  is supported by side walls  250   a  and  250   c  because opposing ends of stair steps  210  are received in cutouts  280  and supported therein. In addition, disposed in volume  270  is a concave or arcuate shaped litter return guide, chute or slide  290  having a first end portion  300  thereof connected to an inside surface of center side wall  250   b . Litter return slide  290  may be thin gauge aluminum, or a suitable durable plastic material, such as acrylonitrile-butadiene styrene. First end portion  300  of litter return slide  290  is connected to the inside surface of center side wall  250   b  by any convenient means, such as by at least one suitable screw fastener (not shown) or by a suitable epoxy adhesive. A second end portion  310  of litter return slide  290  extends through litter return window  70  that is formed in previously mentioned front base panel  60 . 
     Referring yet again to  FIGS. 1 ,  2 ,  3 ,  4  and  5 , as cat  110  traverses stair steps  210  belonging to pathway  200 , tracked litter clinging to paws  115  will be dislodged from paws  115  due to textured surface  230  of stair steps  210  and due to the mechanical friction occurring between paws  115  and stair steps  210 . As the tracked litter is dislodged from paws  115  by stair steps  210 , the tracked litter will fall from the curved or convex surface  230  of stair steps  210  and through slots  220 . As the tracked litter falls through slots  220 , the tracked litter will be received onto litter return slide  290  and slide downwardly therealong. As the tracked litter slides downwardly along litter return slide  290 , the tracked litter will pass through litter return window  70  to be returned to litter  100  in container  20 . In this manner, first embodiment apparatus  10  catches litter tracked from container  20  by cat  110  and automatically and simultaneously returns the tracked litter to container  20 . 
     As best seen in  FIGS. 3 and 4 , litter return slide  290  divides volume  270 , so as to define a compartment  320  between litter return slide  290 , side walls  250   a/b/c  and floor  260 . Compartment  320  may be used to store cleaning materials and/or litter bags  330 , if desired. The cleaning materials are used for cleaning litter return slide  290  and other portions of first embodiment apparatus  10  and the litter bags are used for disposal of soiled litter that is placed into the litter bags. The cleaning materials and litter bags  330  form no part of the present invention. A hinged door  333  is formed in center side wall  250   b  for allowing access to compartment  320 . Door  333  is connected to center side wall  250   b  by means of at least one hinge  335  and can be locked in a closed position, such as by a hook fastener arrangement  337 . 
     With particular reference to  FIG. 4 , first embodiment apparatus  10  is illustrated as including three separate enclosures. In other words, first embodiment apparatus  10  is illustrated as including previously mentioned base  30 , cover  120  and support structure  240  as separate enclosures that can be assembled into a single unit. However, it should be appreciated, based on applicant&#39;s teachings herein, that base  30 , cover  120  and support structure  240  may be manufactured as a single-piece enclosure rather than as a three-piece enclosure that is subsequently assembled together. That is, base  30 , cover  20  and support structure  240  may be manufactured as a single unit, so as to prevent inadvertent formation of open seems or gaps in first embodiment apparatus  10 . Although unlikely, inadvertent formation of open seems or gaps might occur during assembly of the three-piece configuration of first embodiment apparatus  10 . A single-piece configuration, rather than a three-piece configuration, provides added assurance that open seems or gaps are prevented. Such a construction prevents litter that may fall from cat  110  otherwise passing through such open seems or gaps to land outside first embodiment apparatus  10 . 
     Turning now to  FIG. 6 , there is shown a second embodiment apparatus, generally referred to as  340 , for catching and returning litter being tracked therefrom. Second embodiment apparatus  340  is substantially similar to first embodiment apparatus  10 , except that a pair of barriers  350   a  and  350   b  are removably connected to opposing side edges of pathway  200 . Barriers  350   a/b  discourage cat  110  from prematurely leaving pathway  200  before completely traversing pathway  200 . Prematurely leaving pathway  200  reduces the likelihood that sufficient tracked litter will be removed from paws  115  of cat  110 . 
     Referring to  FIG. 7 , there is shown a third embodiment apparatus, generally referred to as  360 , for catching and returning litter being tracked therefrom. Third embodiment apparatus  360  is substantially similar to first embodiment apparatus  10 , except that a rubberized screen, mesh or grate  370  is mounted on top of and spans stair steps  210 . It has been observed that cat  110  may sometimes prefer traversing pathway  200  when pathway  200  has grate  370  thereon. This aspect of cat behavior can be advantageously used to encourage cat  110  to traverse pathway  200 , so that tracked litter is removed from paws  115  of cat  110 . In addition, it may be appreciated that, when grate  370  is present, some of stair steps  210  may be removed, if desired. However, in this case, it is desirable that one or more middle-most stair steps  210  remain to support the weight of cat  110  as cat  110  walks across grate  370 . 
     Referring to  FIG. 8 , there is shown a fourth embodiment apparatus, generally referred to as  380 , for catching and returning litter being tracked therefrom. Fourth embodiment apparatus  380  is substantially similar to first embodiment apparatus  10 , except that brush assembly  190  includes a plurality of substantially longer rubberized bristles  390 . The substantially longer bristles  390  form an obstruction at opening  155  for slowing exit of cat  110  through the opening  155 . That is, the substantially longer bristles  390  are longer than previously mentioned bristles  195 . Substantially longer bristles  390  are sufficiently long to contact cat  110  and interfere with cat&#39;s  110  exit through opening  155  for reasons disclosed presently. In this regard, it has been observed that cat  110  may leap over the length of pathway  200  when exiting opening  155 , rather than walking on pathway  200 . When this occurs, paws  115  of cat  110  will not contact stair steps  210  in order to remove litter from paws  115 . Therefore, substantially longer rubberized bristles  390  will contact cat  110  as cat  110  exits opening  155  and cause cat  110  to pause long enough at opening  155  to prevent cat  110  from gaining enough momentum to leap over the length of pathway  200 . 
     Referring to  FIGS. 9 and 10 , there is shown a fifth embodiment apparatus, generally referred to as  400 , for catching and returning litter being tracked therefrom. Fifth embodiment apparatus  400  is substantially similar to first embodiment apparatus  10 , except that a hinged, removable door assembly, generally referred to as  410 , is substituted for brush assembly  190 . Door assembly  410  forms an obstruction at opening  155  for slowing exit of cat  110  through the opening  155 . More specifically, door assembly  410  includes a support plate  420  disposed above opening  155  and connected to cover  120 . Support plate  420  is disposed above opening  155  and connected to cover  120  by removable fastener means, such as by a suitable epoxy adhesive (not shown) or at least one screw  197 . As another example, door assembly  410  may be connected to cover  120  by means of a pressure latch (not shown), clip (also not shown) or other suitable removable fastener means. Door assembly  410  includes a panel or door  430  that is suspended from support plate  420 . Door  430  is rotatably connected to support plate  420 , so that door  430  is capable of swinging, pivoting or rotating, relative to support plate  420 . In this regard, door  430  will swing, pivot or rotate in the direction of arrow  435  about a horizontal fixed axis of rotation  437 . 
     Referring again to  FIGS. 9 and 10 , an elastic member, such as a spring  440 , has a first end portion  450  thereof connected to support plate  420  and a second end portion  460  thereof connected to door  430 , as shown. First end portion  450  and second end portion  460  of spring  440  are connected to support plate  420  and door  430 , respectively, by any suitable means, such as by a suitable epoxy adhesive, weldments, screws, bolts or the like. Door  430  contacts cat  110  and interferes with cat&#39;s  110  exit through opening  155  for reasons disclosed presently. In this regard, it has been observed that cat  110  may leap over the length of pathway  200  when exiting opening  155 , rather than walking on pathway  200 , as previously mentioned. When this occurs, paws  115  of cat  110  will not contact stair steps  210  in order to remove litter from paws  115 . Spring  440  compresses or contracts as door  430  outwardly and upwardly rotates about axis  435 . The spring constant of spring  440  is selected so as to provide sufficient resistance to cat  100  when cat  110  pushes against door  430  to exit opening  155 . In this manner, door  430  causes cat  110  to pause long enough at opening  155  to prevent cat  110  from gaining enough momentum to leap over the length of pathway  200 . Spring  440  is elastic, as previously mentioned. Therefore, spring  440  will relax or expand and cause door  430  to downwardly rotate about axis  435  to a vertical position after cat  110  exits opening  155 . The configuration of door  430  also allows cat  110  ready access to the interior of container  30 . In this regard, door  430  will inwardly and upwardly rotate about axis  435  as cat  110  contacts door  430  to enter container  20  through opening  155 . Thus, spring  400 , in combination with door  430 , simultaneously provides ready egress out of container  20  and ready ingress into container  20  as wells as preventing cat  110  from leaping over pathway  200 . 
     Still referring to  FIGS. 9 and 10 , and as previously mentioned, door assembly  410  is connected to cover  120  by removable fastener means, such as by an adhesive, at least one screw  197 , a pressure latch, clip or other suitable removable fastener means. Removing the adhesive, screw  197 , pressure latch, clip or other fastener means allows removal of support plate  420 . In this manner, door assembly  410  can be removed by removing support plate  420 , when door assembly  410  is not needed. 
     Illustrative Methods 
     An illustrative method associated with an exemplary embodiment for assembling an apparatus for catching and returning litter being tracked therefrom will now be described. 
     Referring to  FIG. 11 , an illustrative method  470  that is provided for assembling an apparatus for catching and returning litter being tracked therefrom starts at a block  480 . At a block  490 , a container for containing the litter is provided, the container defining an opening for allowing exit of an animal tracking litter from the container and defining a litter return window for allowing return of the tracked litter to the container. At a block  500 , a pathway is extended from the opening for travel therealong of the animal exiting the opening, the animal tracking the litter from the container and along the pathway, the pathway defining a slot therethrough for passage of the tracked litter through the slot. At a block  510 , a litter return slide is disposed beneath the slot and through the litter return window for catching the tracked litter passing through the slot and for slidably returning the tracked litter through the litter return window and into the container. The method stops at a block  520 . 
     Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. For example, the apparatus may be made from a transparent plastic material, such as acrylic (i.e., polymethlamethacylate) for viewing the interior of container  20  and support structure  240 . Ability to view the interior of container  20  and support structure  240  assists in determining when apparatus  10 / 340 / 360  needs to be cleaned and the litter  100  emptied. Accordingly, the description hereinabove is not intended to limit the invention, except as indicated in the following claims.