Lemming
Small Arctic rodent known for population cycles and a persistent suicide myth.
Lemmings are small rodents that live in or near the Arctic, primarily in tundra environments. Along with voles and muskrats, they belong to the subfamily Arvicolinae (also called Microtinae), which is part of the superfamily Muroidea—the same group that includes rats, mice, hamsters, and gerbils. In the Arctic ecosystem, lemmings serve a vital role: they graze on mosses and grasses and are the main food source for most Arctic carnivores. A persistent myth claims that lemmings follow a herd instinct and leap off cliffs in mass suicide.
**Description and habitat** Lemmings are about 13–18 cm (5–7 in) long and weigh roughly 23–34 g (0.8–1.2 oz). They have a rounded body covered in long, soft brown and black fur, with a very short tail, a stubby hairy snout, short legs, and small ears. A flattened claw on the first digit of each front foot helps them dig through snow. They are herbivores, eating mostly mosses and grasses, and also forage through the snow for berries, leaves, shoots, roots, bulbs, and lichens. Lemmings tend to choose their preferred plants more often than those plants appear in the environment, and they digest grasses and sedges less efficiently than related voles do. Like other rodents, their incisors grow continuously, allowing them to chew tough plants. They do not hibernate during the harsh northern winter; instead, they stay active by burrowing through the snow. In winter, they live in large tunnel systems beneath the snow, which offer protection from predators. These burrows include rest areas, toilet areas, and nesting rooms, and nests are built from grasses, feathers, and muskox wool (qiviut). In spring, lemmings move to higher ground, living on mountain heaths or in forests and breeding continuously before returning to the tundra in autumn. They can live up to twenty-four months, though their life expectancy is usually given as one year due to predation.
**Behaviour** Like many rodents, lemmings experience periodic population booms and then scatter in all directions, searching for food and shelter their usual habitats cannot provide. The Norway lemming and West Siberian lemming are among the few vertebrates whose reproduction is so rapid that their population changes are chaotic, rather than following a steady growth to a limit or regular cycles. Why lemming numbers fluctuate so dramatically roughly every four years, then drop nearly t
- length
- 13–18 cm (5–7 in)
- weight
- 23–34 g (0.8–1.2 oz)
- lifespan
- up to 24 months, typically 1 year due to predation
- diet
- herbivorous: mosses, grasses, berries, leaves, shoots, roots, bulbs, lichens
- habitat
- Arctic tundra, mountain heaths, forests
- known_for
- periodic population booms and the myth of mass suicide
Lore & Background
Lemmings measure around 13–18 cm in length and weigh 23–34 g. They have rounded bodies with brown and black long, soft fur, a very short tail, stubby hairy snout, short legs, and small ears. A flattened claw on the first digit of their front feet helps them dig in snow. They are herbivorous, feeding mostly on mosses and grasses, and also forage through snow for berries, leaves, shoots, roots, bulbs, and lichens. They digest grasses and sedges less effectively than related voles. Like other rodents, their incisors grow continuously. Lemmings do not hibernate; they remain active in winter, burrowing through snow and living in large tunnel systems with rest areas, toilet areas, and nesting rooms made from grasses, feathers, and muskox wool. In spring they move to higher ground, breeding continuously before returning to the tundra in autumn.
Reader's Guide
Lemmings are significant for their role in the Arctic food web and their dramatic population fluctuations. Their numbers boom roughly every four years, then drop to near extinction, for reasons not fully understood. This behavior, combined with their conspicuous coloration and aggression toward predators, has fueled a long-standing myth that they commit mass suicide by jumping off cliffs or drowning. The myth was popularized by the 1958 Disney film White Wilderness, which faked footage by throwing lemmings off a cliff. In reality, their migrations are driven by population density, not suicidal intent. The misconception dates back at least to the late 19th century and has been used allegorically to describe humans who follow trends without independent thought. Lemmings' population cycles also affect predator behavior, potentially fueling irruptions of snowy owls to areas further south. Some evidence suggests predator populations, particularly stoats, may be more closely involved in lemming population changes than previously thought.
Did You Know?
- Lemmings have a flattened claw on the first digit of their front feet to help dig in snow.
- The Norway lemming and West Siberian lemming are among the few vertebrates with chaotic population fluctuations.
- The 1958 Disney film White Wilderness faked lemming mass suicide by throwing them off a cliff from a truck.
- Lemmings do not hibernate; they remain active in winter, burrowing through snow in large tunnel systems.
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