Brown rat  (Rattus norvegicus)

The brown or Norway rat is a supreme generalist; its opportunistic lifestyle, agility and prolific breeding potential have helped it to colonise practically every part of the world (2). The fur of this rat varies in colour but is generally brown or greyish-brown with some black hairs, becoming paler on the underside (2). The tail is long and largely hairless, the naked ears are prominent (1) and the eyes are relatively small (2).