The domestic cat (Felis catus or Felis silvestris catus, previously Felis domesticus) is a small, usually furry, domesticated, carnivorous mammal. It is often called the housecat when kept as an indoor pet, or simply the cat when there is no need to distinguish it from other felids and felines. Cats are valued by humans for companionship and ability to hunt vermin and household pests. They are primarily nocturnal.
Cats are a cosmopolitan species and are found across much of the world. They are extremely adaptable and are now present on all continents except Antarctica, and on 118 of the 131 main groups of islands – even on sub-Antarctic islands such as the Kerguelen Islands. Feral cats can live in forests, grasslands, tundra, coastal areas, agricultural land, scrublands, urban areas and wetlands. Their habitats even include small oceanic islands with no human inhabitants. This ability to thrive in almost any terrestrial habitat has led to the cat's designation as one of the world's worst invasive species. Despite this general adaptability, the close relatives of domestic cats, the African Wildcat (Felis silvestris lybica) and the Arabian Sand Cat (Felis margarita) both inhabit desert environments, and domestic cats still show similar adaptations and behaviors.