The majority of domestic cats lead solitary lives and resent or fear competition for food, territory, and shelter. However, two or more cats that share a home can become friends, especially if they are littermates. Others, at best, cease hostilities and settle down together with indifference. Among feral cats there is a much greater degree of sociability.
Because food supplies can be scarce and unreliable, any feral cats within one area tend to be drawn to a common food source, such as a garbage dump, a feeding station organized by cat welfare organizations, or an empty building overrun by rats and mice. Out of necessity, these cats tolerate each other and will share resources with minimal aggression.
Where a few feral cats have found shelter, a colony can build up, which over the years can amount to dozens of animals of several interrelated generations. Any unneutered females attract toms—entire males—and frequent matings produce two or more litters of kittens a year for each female.
Established colonies are very much matriarchal societies, with a core population of females that often form close bonds. Female cats have been observed sharing birth dens and cooperatively nursing and raising litters of kittens, taking turns guarding the family when one of the mothers goes out hunting.
Feral females have even been known to present a combined front to fight off marauding toms, which are a constant peril with their desire to kill off kittens and so bring the females back into season for further matings.
As a feral colony expands, the dynamic within it changes, with stronger toms ousting weaker rivals that then either hang around the periphery of the group or strike out on their own to find more congenial territory. Occasionally, males born within a colony do become accepted by the senior members simply because of their familiarity, but a strange tom attempting to infiltrate the group is usually rejected vigorously.