An enclosure for a household pet is described that has a top portion and a bottom portion. The enclosure can have a plurality of substantially vertical sides extending between the bottom portion and the top portion to form an enclosure for a household pet. At least a first side and a second side of the plurality of substantially vertical sides can be configured to be disposed adjacent to two sides of a larger enclosure. At least a third side of the plurality of substantially vertical sides configured to be disposed away from the sides of the larger enclosure. The third side can have an aperture to allow access into the enclosure by a household pet. The enclosure can have at least one connecting device configured to attach the enclosure for the household pet to the larger enclosure.
