fig1 shows an exploded view of a simple small animal environment according to the an embodiment of the present invention . the main small animal enclosure 1 is provided with a flip top lid opening 3 at the top of the enclosure . a wire grid floor 5 fits onto the open bottom of the enclosure 1 . side wall through holes 7 are formed on the two side and back walls of the enclosure . two of the through holes 7 are closed off with vented door closures 9 . a u shaped double track 11 is formed on the outside wall around the through holes 7 . a metal protector 8 slides over the exposed edge of the through hole . a flange receptacle 13 is formed at the bottom of the u shaped track 11 on the outside track . a single top wall through hole 15 is formed on the side of the lid opening 3 . the small animal enclosure 1 snaps onto the litter tray 17 at the opened bottom of the enclosure . a water bottle 19 is formed with a bottom u shaped bead 21 to engage an outside track of the u shaped double 11 . a door slider 23 is formed with and opened end 25 and a closed end with air holes 27 . a straight tube 29 is formed with variably spaced outside beads 31 . when the straight tube 29 is inserted into the top wall through hole 15 the beads will hold it at a desired height above the wire grid 5 . a metal ring 33 may be fitted over the inside end of the straight tube to resist gnawing . a tube lip 30 is provided at the ends of the tube to facilitate engagement with the outer track of the u shaped double track 13 . at the top of the straight tube 29 a tower top 35 is attached using a linking ring 37 . a flip top lid opening 3 is hinged onto the tower top 35 . fig2 and 4 illustrates the u shaped double track system 11 of the present invention and the use of the door slider 23 to open and close the passageway . the inside track 39 accommodates the door slider 23 , while the outside track 41 joins tubes , accessories or other housings . fig3 and 4 illustrate the door slider 23 in place in the inside track 39 . in fig3 the open end of the door slider 25 is engaged and in fig4 the passage is closed off when the closed end of the door slider 27 is engaged . it is readily apparent that the door slider engages and disengages from the inside track without any effect on the outside track . a passageway can therefore be closed or opened without disengaging any tube or accessory which is engaged in the outer track 41 . fig5 illustrates a tower top 35 of the present invention with an open flip top 3 . the flip top 35 is hinged to the bottom portion of the tower top at the back end 43 . both the back edge of the flip top 3 and the top back of the tower top 35 are slanted so that the edges act as a stop to keep the flip top level when opened . a small animal can sit on this opened flip top for play with the hobbyist . the inner surface of the lip may be formed with bumps or runners to keep the animal from slipping on the plastic surface . the tower top 35 engages a tube at the bottom opening 47 . fig6 illustrates the quarter round tube 49 of the present invention . linking lips 30 are provided at either ends to allow engagement with the double track system or linking with other tubes using linking rings . internal ridges , 51 may be formed on the inner surface of the tube to aid the animal in moving through the tube . fig7 illustrates three quarter round tubes 49 connected using linking rings 37 with a y tube 53 to form a circular passageway . the y tube 53 has a through opening on the side wall 55 . the circular passage can be joined to other tubes or directly to an enclosure using this passageway . fig8 shows a bubble cap closure 57 which can be used to close off a the or passageway from an enclosure , the lip 59 engages with the outside track of the u shaped double track side wall opening . a linking ring can be added to the lip to facilitate connection with the end of a tube , or for closing off a top through hole . the bubble cap is shaped to protrude out from the passageway so that a small animal can crawl into the cap . this provides added viewing variety for the hobbyist . fig9 illustrates a small animal environment of the present invention with a plurality of attached accessories and tubes . the enclosure 1 has a wire grid floor 5 and litter tray base 17 . a bubble cap closure caps off an unused upper wall through hole 15 . a straight tube 29 extends through a second upper wall through hole 15 . a tower top 35 connects at the top of the straight tube . in this embodiment the tower top is a conventional unit without the novel flip top platform of the present invention . also the enclosure lid 64 is not of the flip top type , but is full removable and secured in place by a lid band 66 . air vents 60 are spaced throughout the enclosure 1 to provide adequate ventilation . an exercise wheel 61 having a linking lip 30 engages the outside track of a u shaped double track 11 at one passageway . a door slider in the open position is engaged in the inner track . the wheel has a unique removable waste catcher 63 that is slidably mounted at the bottom of the wheel . the outer wheel housing is slanted away from center so that animal droppings fall to the outer edge at the bottom of the wheel the waste falls into the waste cup through a gap between the outer wheel housing 65 and the inner wheel housing 67 . this embodiment of the present invention also illustrates the unique relationship between the quarter round tubes and through hole passageways of the present invention . three quarter round tubes are connected with linking rings 37 to form a three quarter circle runway . one tube end is engaged in the outside track of a u shaped double track system on one side wall , and the tube opposite tube end engages the double track system of an adjacent wall . the key inventive feature of this aspect of the present invention is the relationship between the three quarter circle formed by the quarter round tubes and the spacing of the through holes on the adjacent side walls . the through holes must be spaced so that they align with the circumference of the three quarter circle pathway formed by three connected quarter round tubes , at points equating to three quarters of a completed circular pathway that would be formed by four quarter round tubes . in this manner the opposing opened ends of the three quarter circle pathway can engage the through hole connections on the adjacent walls . based upon this aspect of the present invention , the small animal an then provide with an exercise path that exists and enters that enclosure , yet takes up an minimum of space and keeps the animal securely in the small animal environment . the hobbyist is provided with an excellent opportunity to view the animal at play . furthermore , door sliders 23 are engaged on in both inside tracks of the two passageways . these door sliders can be reversed in order to close off the runway for cleaning , maintenance or when the hobbyist wants to reconfigure the environment . fig1 illustrates a alternate embodiment of the present invention . in this embodiment and outside feeding accessory 71 is engaged at one passageway . the door slider 23 allows the hobbyist to close off the passageway to regulate feeding , and to remove the feeder for cleaning . the outside feeder also does not use valuable interior living area . a tower top 35 is connected to a quarter round tube and extends for a side passageway . an item of small animal furniture 73 is visible inside the enclosure . this furniture is uniquely designed to lock onto the wire grid floor 5 to prevent movement inside the enclosure . the preferable locking mechanism is to form undercut projections at the bottom of the furniture item hat can hook onto the wires if the floor grid . this figure illustrates the relationship that can be developed between the top wall through holes and the quarter round tubes to form an arched passageway above the enclosure . two upper wall through holes 15 are spaced on the top wall of the enclosure 1 so that when straight tubes 29 are extended through these through holes the top ends of the straight tubes can be joined together by two quarter round tubes . the upper through holes 15 must be spaced so that they align with the circumference of the half circle pathway formed by two joined quarter round tubes , at points equating to one half of a completed circle that would be formed by quarter round tubes . this feature of the present invention offers the unique advantages for small animal care and enjoyment discussed above relating to the three quarter round pathway . in addition , this arrangement allows the small animal to simulate free climb up out of the enclosure and back down into the enclosure while being securely confined in the hamster environment . fig1 illustrates a complete multienclosure small animal environment . this environment can house multiple small animals in the various enclosures . the configuration is facilitated by the ability to easily connect tubes and accessories using the u shaped double track system , and the ability to close off various component parts using door sliders . the use of quarter round tubes offers the ability to form more natural and pleasing tunnel assemblies to promote exercise for the small animals and enjoyment fore the hobbyist . it is readily apparent that the above described small animal environment meets all of the objectives mentioned as well as providing other advantages for maintaining small animals . it should be understood that the specific form of the invention here and above described is intended to be representative only , as certain modifications within the scope of these teachings will be apparent to those skilled in the art of small animal care . accordingly , reference should be made to the following claims in determining the full scope of the invention .
a small animal living environment system formed from small animal enclosures fabricated from transparent thermoplastic material . the enclosures having a lid opening large enough to accommodate a human hand and ventilation openings of sufficient size and number to allow for air passage through the enclosure . the enclosures also have a plurality of through openings on the walls of the enclosure , for the passage of small animals therethrough and an attaching means formed at the opening passage for the attachment of tunnel tubes , and small animal living accessories . the attaching means is formed from a u shaped track system wherein an outside edge of the opening passage is formed into at least one u shaped channel on the lower portion of the opening passage , and tunnel tubes are formed with a protruding lip on the outside edge of the tube opening so that the lip may be securely fit into the channel of the u shaped track attaching means .