These lemmings are short, stockily built creatures. The third and fourth claws of their forefeet are unusually large and well adapted to digging. In summer these claws are about normal in appearance, but with the approach of winter they develop a peculiar double effect in a vertical plane, which makes them very strong and well suited for burrowing in the frozen earth or in snow and ice. This remarkable development of the third and fourth claws in winter distinguishes Dicrostonyx from all other small rodents. The ears of this genus are so small that they are little more than rims, completely hidden in the fur.
Females have eight mammae.
These lemmings occur on the treeless arctic tundra, mainly in dry, sandy, and gravelly areas with some plant cover. They are active throughout the year. During the summer they live in shallow underground burrows or under rocks. Faint runways on the surface of the ground may also be made, but these paths are not as pronounced as those of some other microtines. In the winter collared lemmings place their grass nests on the surface of the earth under a snowbank or even in the middle of a snowbank.