The farm cat, also known as a barn cat, is a domestic cat, usually of mixed breed, that lives primarily out-of-doors, in a feral or semi-feral condition on agricultural properties, usually sheltering in outbuildings. They eat assorted vermin such as rodents and other small animals that live in or around outbuildings and farm fields. The need for the farm cat may have been the original reason cats were domesticated: to keep rodents from consuming or contaminating grain crops stored for later human consumption. They are still commonly kept for the purpose of catching undesired vermin found on farms and ranches, which would otherwise eat or contaminate crops, especially grain or feed stocks.
Archeological evidence suggests that the earliest domestication of cats occurred about 7500 BC and was motivated by the human need to safeguard grain stores from rodent pests.
Farm cats live in a variety of conditions. Some are feral with minimal human contact, no veterinary care, and derive sustenance solely from their job of lowering the mouse and rat populations. Lack of a guaranteed food supply, internal parasites, and greater physical exertion tends to make these cats thinner than their house cat counterparts, with a shorter lifespan. Others are kept as part-time pets, living both indoors and out, roaming freely, yet allowed inside to be fed supplemental cat food on a regular basis, and given routine veterinary care. Yet others live outdoors or in outbuildings full-time in semi-feral conditions, but are still tamed to be friendly toward humans and may be given basic veterinary care. All are subject to some risks inherent to outdoor life. Their prey may transmit parasites and disease, they may be injured by various means, and they can be struck by vehicles. Predation is also possible: cats are eaten by raccoons, owls, coyotes, and other animals that prey on creatures of their size.