The Stoat (Mustela erminea), also known as the Short-tailed Weasel, is a species of Mustelidae native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip. The name ermine is often, but not always, used for the animal in its pure white winter coat, or the fur thereof.
The American mink has also been introduced to large portions of Europe where it is classified as an invasive species, linked with the decline of several native species including the European mink.
Minks and weasels are members of the mustelid animal family. Mustelidae share a few basic characteristics. One commonality among mustelids is the possession of anal scent glands that release a musty substance the animals use for defense and territorial marking. Weasels, minks and other Mustelidae -- including martens, fishers, ferrets, polecats, wolverines and badgers -- differ in size, habitat and diet; but all are carnivores, and most are aggressive and seemingly fearless animals.