The Norway lemming, also Norwegian lemming (Lemmus lemmus) is a common species of lemming found in northern Fennoscandia. It is the only vertebrate species endemic to the region. The Norway lemming dwells in tundra and fells, and prefers to live near water. Adults feed primarily on sedges, grasses and moss. They are active at both day and night, alternating naps with periods of activity.

The Norway lemming has a dramatic three- to four-year population cycle, in which the species' population periodically rises to unsustainable levels, leading to high mortality, which causes the population to crash again.

The Norway lemming spends the winter in nests under the snow. When the spring thaws begin and the snow starts to collapse, they must migrate to higher ground, where the snow is still firm enough for safety, or, more commonly, to lower ground, where they spend the summer months. In autumn, they must time their movement back to sheltered higher ground carefully, leaving after alpine snow cover is available for their burrows and nests, and before the lowlands are made uninhabitable by frost and ice.

When confronted with a predator, Norway lemmings do not try to run away; they instead start attacking the predator/intruder. They are also known to attack approaching humans.


From Wikipedia; The Free Encyclopedia.