The Stoat is a specialist predator of small mammals (especially rodents and small lagomorphs), however it also occasionally feed on birds’ eggs, fish, lizards, amphibians, invertebrates, berries and carrion (King 1983). It sometimes attacks animals considerably larger than itself, such as adult hares. Food may be stored underground for the winter. The Stoat is found in many habitats, from open tundra to deep forest, but seems to prefer areas with vegetative or rocky cover. The local distribution of Stoats is broadly related to that of small rodents and lagomorphs. They usually avoid dense forest and deserts, and settle in forest edge habitats, scrub, marshes, riparian woodlands, hedgerows, and alpine meadows.

It is a solitary animal – there are no pair bonds between adults. Mating occurs once a year, from March to September – depending on the geographic region. The Stoat has delayed implantation, varying from 240 to 390 days. Litter size averages between six and eight cubs (range 2–18). It is active both day and night. The home range is around 1–200 ha, and varies with sex and region (King and Powell 2007). Population density fluctuates with prey abundance. Under good conditions there may be an individual for every 10 ha. The home ranges of the males includes portions of those of the females. Resident animals of both sexes maintain exclusive territories. Boundaries of these territories are regularly patrolled and scent–marked, and neighbours usually avoid one another. Dens are in hollow trees, burrows, rock crevices, sometimes in nests of prey. It maintains several nests within its range, which are lined with dry vegetation or the fur and feathers of its prey. The Stoat is primarily terrestrial but swims well and easily climbs trees to great heights, where they visit the nests of birds and squirrels. It generally hunts in a zigzag pattern, progressing by series of leaps of up to 50 cm each. It can easily run over the snow, and if pursued, it may move under the snow. It may travel 10–15 km in a night, though the average hunt covers 1.3 km. Its slender body allows it to enter and move quickly through the burrows and tunnels of its prey.

The Stoat occurs throughout Europe except southern Europe and the Mediterranean. It is absent from Iceland, Svalbard, some small North Atlantic islands, and the Mediterranean islands. Its vertical range is from sea level to 3,000 m in Europe (Kotia et al. 2011).

The Stoat has a wide Holarctic distribution, covering most of Europe, northern Asia and North America. Outside of Europe, the Stoat occurs from Arctic Siberia south to northern Mongolia and north-eastern China. It is absent in vast arid plains and deserts of Middle and Central Asia. The Stoat has a restricted distribution in the Himalayas, where it is confined to the west in Ladakh (India), Pakistan and Afghanistan. The Stoat is found on many Arctic Islands and some Pacific islands (some Kuril Islands, Sakhalin, Hokkaido and northern Honshu). In North America, it occurs from Alaska, Greenland, and the Canadian Arctic south through most of the northern United States to the Great Lakes region and the southern part of North American Cordillera. The Stoat has been introduced to New Zealand.

The Stoat is listed on Appendix III of the Bern Convention. It occurs in many protected areas across its range. Monitoring of exploitation is required by the Bern Convention (R. McDonald pers. comm. 2006). The species is protected under national legislation in some range states (e.g. Spain), although this is not necessarily enforced (Palomo and Gisbert 2002). However, in many parts of its global range the species is not protected and trapping is legal.

Population monitoring and further research into the threats faced is recommended for this species.