Weasels /ˈwiːzəl/ are mammals forming the genus Mustela of the Mustelidae family. The genus includes the weasels, European polecats, stoats, ferrets and European minks. They are small, active predators, long and slender with short legs. The Mustelidae family (which also includes badgers, otters and wolverines) is often referred to as the weasel family. In the UK, the term "weasel" usually refers to the smallest species Mustela nivalis (also known as the least weasel).