The arctic fox

The arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of theNorthern Hemisphere and is common throughout the Arctic tundra biome.It is well adapted to living in cold environments. It has a deep thick fur which is brown in summer and white in winter. It averages in size at about 85.3 cm (33.6 in) in body length, with a generally rounded body shape to minimize the escape of body heat.

They prey on any small animals they can find, including lemmings, voles, ringed seal pups, fish, and seabirds. They will also eat carrion, berries, and seaweed. They form monogamous pairs during the breeding season and usually stay together in family groups of multiple generations in complex underground dens.

The arctic fox lives in some of the most frigid extremes on the planet. Among its adaptations for cold survival is its deep, thick fur,

 a system of countercurrent heat exchange in the circulation of paws to retain core temperature, and a good supply of body fat. The fox has a low surface area to volume ratio, as evidenced by its generally rounded body shape, short muzzle and legs, and short, thick ears. Since less of its surface area is exposed to the arctic cold, less heat escapes the body. Its furry paws allow it to walk on ice in search of food. The arctic fox has such keen hearing that it can precisely locate the position of prey under the snow. When it finds prey, it pounces and punches through the snow to catch its victim. Its fur changes color with the seasons: in the winter it is white to blend in with snow, while in the summer it is brown.