Feral cats are wild cats that are unfamiliar with humans and roam freely in urban or rural areas. The numbers of feral cats are not known, but estimates of the US feral population range from 25 to 60 million.
Feral cats may live alone, but most are found in large groups called feral colonies, which occupy a specific territory and are usually associated with a source of food. Famous feral cat colonies are found in Rome around the Colosseum and Forum Romanum, with cats at some of these sites being fed and vetted by volunteers.
Public attitudes towards feral cats vary widely: ranging from seeing them as free-ranging pets, to regarding them as vermin. One common approach to reducing the feral cat population is termed trap-neuter-return, where the cats are trapped, neutered, immunized against rabies and the feline leukemia virus, and then released.
Before releasing them back into their feral colonies, the attending veterinarian often nips the tip off one ear to mark the feral as neutered and inoculated, since these cats may be trapped again.
Volunteers continue to feed and give care to these cats throughout their lives, and not only is their lifespan greatly increased, but behavior and nuisance problems, due to competition for food, are also greatly reduced.
