This highly aquatic member of the weasel family is found throughout most of northern North America. Large males may reach a total length of more than 60 cm (2 ft.). As adults, American minks are bold, ferocious and virtually untameable. It has been observed, however, that if they are captured as kittens they are playful and can become attached to the person who cares for them.

A solitary, mainly nocturnal animal, the American mink is active throughout the year. It is a skillful hunter and preys on a wide variety of game including meadow voles and other small mammals, muskrats, fish, crayfish, frogs and insects. The males tend to take larger prey items than females, which are smaller. This ecological division of prey between the two sexes helps the females, who must care for and feed the kits by themselves while sharing hunting grounds with the males. There is an average of five kits per litter.

Its principal enemies are the Great Horned Owl, bobcats, wolves and coyotes. Humans hunt the American mink for its commercially valuable fur.

This species has been deliberately introduced as a fur animal into northern Russia and other parts of Europe where wild populations have become established. The American mink has proven to be excellent at colonizing new habitats and is proving to be a serious competitor of the indigenous European mink, Mustela lutreola.