Weasels ( /ˈwiːzəl/) are mammals forming the genus Mustela of the Mustelidae family. They are small, active predators, long and slender with short legs.
Weasels vary in length from 12 to 45 centimetres (5 to 18 in), and usually have a red or brown upper coat and a white belly; some populations of some species moult to a wholly white coat in winter. They have long slender bodies, which enable them to follow their prey into burrows. Their tails may be from 22 to 33 centimetres (9 to 13 in) long. Weasels have a reputation for cleverness and guile.
Weasels feed on small mammals, and have from time to time been considered vermin since some species took poultry from farms, or rabbits from commercial warrens. Weasels occur all across the world except for Antarctica, Australia, and neighbouring islands.