The weasel family, also called the mustelids, includes weasels, stoats, minks, ferrets, polecats, martens, the sable, otters, badgers and the wolverine. They are carnivores with long bodies, short legs and often long tails. Mustelids can be found on and under the ground, in the trees or in the water. Most feed on smaller mammals, especially rodents, but some will also eat worms, fruit and insects. Apart from some otters and badgers, the weasel family are solitary mammals, keeping to their own territories and fighting if these are invaded. Males and females usually come together only to breed.

Stoat

Distinguished from least weasels by their larger size and black tips to their tails, stoats are ferocious predators. They will sometimes attack animals over twice their own size. They search for prey inside burrows or in other likely hiding places.

Their slim bodies enable them to chase their quarry along narrow tunnels under the ground or beneath the snow. Stoats kill their prey with a sharp bite to the back of the neck.

Least weasel

The least weasel (also known, simply, as the weasel), although tiny, is a fierce predator. It can attack and kill a rabbit or hare many times its own size, but will normally hunt small rodents or rabbit kittens, chasing its prey down through their burrows or out into the open. It kills by delivering a swift bite to the skull or neck.

American mink

Native to North America, the American mink has been introduced to many parts of Europe, Siberia and South America. It feeds on rabbits, rodents, fish, crustaceans, frogs and birds. Its arrival to Europe resulted in the decline of the European mink, Pyrenean desman and water voles, all of which it attacks and kills.

Wolverine

The wolverine is a heavy, powerful carnivore, capable of preying on animals larger than itself, such as reindeer. Its broad feet allow it to run over the top of the snow, while the reindeer's narrow hooves sink in, giving the pursuing predator a crucial advantage. A solitary hunter, it will also scavenge kills of other animals, using its powerful jaws and chewing muscles to crush thick bones. Its diet also includes small mammals, plants and berries.

Skunks

Distantly related to mustelids but belonging to a different family, the mephitids, are the skunks. All 14 species are from the Americas. Long-clawed and omnivorous, skunks have a bushy tail and a thick black-and-white coat, which protects them from the stings of honeybees, upon which they frequently prey.

​​​​​​​If threatened by a predator itself, the skunk will turn its back on its attacker and spray foul-smelling liquid in its face. It can spray with great accuracy as far as 3 metres (10 feet). Its bold markings warn predators of this weapon, deterring them from attack (which is to the skunk's advantage as it can only use the chemical five or six times; it takes 10 days for a new supply to build up). Most predators, including bears and wolves, are wary, although domestic dogs and the great horned owl often attempt to attack it, despite the risk.