A lemming is a small rodent, that belongs to the Cricetidae family.
They are subniveal (zone in and underneath snowpack) animals and together with voles and muskrats, they make up the subfamily Arvicolinae.
There are around 30 species of lemming.
A lemming’s lifespan is relatively short: 1 year in the wild is average; in captivity, a lemming may live 3 years.
Lemmings weigh from 30 to 110 grams (1 to 4 ounces) and are about 7 to 15 centimeters (3 to 6 inches) long.
Their bodies are stout, their limbs are short, and their tail and ears are tiny to help them conserve heat.
Lemmings have long claws on their forefeet and sharp teeth for gnawing roots.
Like other rodents, their incisors or front teeth grow continuously, allowing them to exist on much tougher forage than would otherwise be possible.
Lemmings have thick, coarse fur that enables them to endure the long, cold winter in their natural habitat.
Their coats come in different colors, depending on species, but most are brown or gray. Some turn white during winter.
Lemmings do not hibernate through the harsh northern winter. They remain active, finding food by burrowing through the snow and using grasses clipped and stored in advance.
Lemmings are herbivores. Their diets consist primarily of moss and grass, but they may also eat some berries, bulbs and lichens.
The food that lemmings eat is not very nutritious, so lemmings must eat lots of it. In fact, they may spend six or more hours every day searching for and eating food.
Lemmings exhibit both diurnal and nocturnal active, often active both night and day.
They are solitary animals by nature, meeting only to mate and then going their separate ways.
Lemmings dig burrows in the snow. Living beneath the snow functions to keep them safe from predators. It also keep them warm, as underground temperatures are typically higher than air temperatures.
Their underground burrows have rest areas, bathrooms and nesting rooms. Lemmings make nests out of grasses, feathers and musk ox wool.
Female lemmings give birth to the baby lemmings after a gestation period of around three weeks. Baby lemmings are born in burrows under the snow which helps to keep the baby lemmings warm and away from the Arctic winter. The mother lemming gives birth to around 7 baby lemmings and feeds the baby lemmings on her milk until they are big enough and strong enough to start looking for food by themselves.
Like all rodents, lemmings have a high reproductive rate and can breed rapidly when food is plentiful.
Although lemmings are similar to other rodents, they differ in their bright colors and aggressiveness toward predators.
When population of lemmings in certain area becomes too large, they migrate in large numbers toward new areas to find food.
Lemmings can swim and may choose to cross a body of water in search of a new habitat. In such cases, many may drown if the body of water is so wide as to stretch their physical capability to the limit.
Contrary to popular belief, lemmings do not commit mass suicide when they migrate. It is a misconception fuelled by the media and video game industries.
In 1955, Carl Barks drew an Uncle Scrooge adventure comic with the title “The Lemming with the Locket.” This comic, which was inspired by a 1953 American Mercury article, showed massive numbers of lemmings jumping over Norwegian cliffs.
Even more influential was a Disney movie called “White Wilderness,” which won an Academy Award for Documentary Feature, in which staged footage was shown with lemmings jumping into certain death after faked scenes of mass migration.
This myth was also used in the Apple Computer 1985 Super Bowl commercial “Lemmings” and the popular 1991 video game Lemmings, in which the player must stop the lemmings from mindlessly marching over cliffs or into traps.
Because of their association with this odd behavior, lemming “suicide” is a frequently used metaphor in reference to people who go along unquestioningly with popular opinion, with potentially dangerous or fatal consequences.