The brown rat, also referred to as common rat, street rat, sewer rat, Hanover rat, Norway rat, Norwegian rat, or wharf rat (Rattus norvegicus), can be found in most parts of the world but is believed to have originated in eastern Asia. It spread partially on foot, and partially by ship. In the wild brown rats tend to stay within a restricted area, provided that it has sufficient food, so it's territory is usually small.
