Modular housing for cats

A modular multi-level pet housing comprising:

• a plurality of multi-sided boxes, each box having a plurality of side walls of a predetermined height, a top and a bottom;
• a plurality of first support columns of a first length generally less than the height of the side walls;
• a plurality of second support columns of a second length generally longer then height of the side walls;
• the first and second support columns having ends with a cross-sectional size and shape that is substantially the same;
• a plurality of coupling members adapted to be received on the ends of the first and second columns;
• the top and bottom of each box being formed with a plurality of holes sized to selectively permit one of the first and second tubular members to fit therethrough, but to prevent a coupling member from fitting therethrough;
• whereby a multi-level pet housing is constructed by stacking one or more boxes on top of a first box resting on a base level in which one of the first support columns is located within the first box aligned with the holes in the top and bottom and have a coupling member mounted thereon, and the second tubular column located within a second box is connected to coupling to secure the second box thereto.