Abstract: A housing for small pet animals includes a pedestal portion 1, a fixing side plate 3 uprightly attached to the pedestal portion 1, an activity wheel 5 with one side opened toward the fixing side plate 3 and the other side closed by closing members 52c. The wheel 5 is disposed above the pedestal portion 1 with the one side closed by the fixing side plate 3. The housing further includes a housing equipment immovably attached to the fixing side plate 3 and disposed in a housing space surrounded by the fixing side plate 3 and the activity wheel 5.

Abstract: An expandable cage assembly has cage connecting insert assemblies. These assemblies include top and bottom terminal connecting insert members and intermediate connecting insert members. Each of the insert members have cage engaging side edges and interconnecting edges. Cage engagement channels are located on the side edges for engaging the cage, and either interconnecting tabs or tab engaging contours are located on the interconnecting edges for connecting to adjacent connecting insert members.

Abstract: A top for a small animal cage provides an access compartment therein. Selective access to the animal by the pet owner is obtained through a hinged lid, and access to the compartment by the animal is provided through openings in the compartment which communicate to the cage interior.

Abstract: A floating island for an aquarium according to the invention includes a board-shaped floating island body, a supporting rod and a fixing device. One or a plurality of the supporting rod are slidably inserted in the floating island body in the direction of the thickness of the floating island body. The supporting rod is fixed in un upright state in an aquarium by a fixing device. The floating island body can stably stay on the water by the supporting rods, and can also automatically move up and down in accordance with the change of the water level.

Abstract: This bottle apparatus includes a flat-sided bottle member for a flush fit against a cage. A flexible, resilient clip member attaches to the cage and engages vertical mounting edges on the water bottle. Outwardly flaring arms serve to guide the bottle into the clip and to spread the clip when the bottle is inserted.

Abstract: An effective track system for guiding a rolling hamster ball includes straight and curved track sections, placed end to end. Each track section has a base and paired support rails protruding upwardly from the base for supporting and guiding the pet exercising ball along the track.