A descriptive study of the use of space and patterns of interaction of 14 unrelated, nonreproductive domestic cats (Felis catus) living together in a singlestory house was undertaken, since these behaviors have rarely been described for cats in this common situation.Within the house, the cats kept to overlapping but individually distinct home ranges. The home ranges of males tended to be slightly larger than those of females, a pattern similar to that found in studies of feral cats outdoors. Three male kittens showed dramatic reductions in home range at approximately one year of age.Almost all individuals had favored spots where they could predictably be found within the rooms they frequented. While some individuals had unique spots that only they used, more com-monly several individuals had the same favored spot within a room. Sharing of such spots was primarily the result of different individuals occupying the spots at different times, a kind of time-sharing rather than physical sharing. Time-sharing groups could be identified, some all female, some all male, some a mix.Certain individuals were identified as dominant or subordinant by their ability to control access to resources and/or by others conceding resources to them. However, overt aggression was rare, and there was no clear hierarchy.Tail positions could be identified and may have played an important role in helping this relatively large group occupy this relatively small home.Density calculations completed at the end of the study indicated that the group was living at approximately 50 times the highest densities observed in most studies of cats outdoors, yet stable groupings were maintained.