Any of several species of small rodents belonging to the family Cricetidae and found primarily in northern temperate and polar regions of North America and Eurasia. Lemmings have short legs, small ears, and long, soft fur. They are 4–7 in. (10–18 cm) long, including the stumpy tail, and are grayish or reddish brown above, paler below. They feed on roots, shoots, and grasses and live in burrows or rock crevices. They are noted for regular population fluctuations, and for their periodic migrations in spring and fall. Those of the Norway lemming (Lemmus lemmus) are the most dramatic, because many of the migrants drown in the sea. However, lemmings are hesitant to enter water and, contrary to legend, do not plunge into the sea in a deliberate death march.