As far as lemmings go, the Norway lemming is one of the larger ones. They grow three to six inches long and weigh up to 130 grams.

Norway lemmings, no matter the gender, have the same brown coat with golden streaks in it all year. These lemmings have a small tail and short limbs that are usually tucked up under their body.

The first digit on each paw is larger and flatter than the others to help tunnel through the snow.

Norway lemmings have year-round thick bodies and heavy coats to hold in body heat, which is useful due to their constant migrating.

As their name suggests, the Norway lemming can be found in Norway, more specifically in Fennoscandia. In fact, it is the one vertebrate species that cannot be found anywhere but in parts of Fennoscandia. Norway lemmings prefer tundra and alpine areas with snow in the winter or constant moisture like bogs.

Norway lemmings are active for 6 hours on average throughout the day or night. During this time, lemmings will roam the area and look for food such as sedges, moss, bark, grass, and more. During rainy winters and freezing temperatures, sources of food can become scarce leading to threatening behaviors from the male lemmings such as boxing and wrestling.

Little is known about the Norway lemming’s mating rituals, but they can reproduce year-round. These lemmings reach sexual maturity extremely early with the youngest recorded pregnant Norway lemming being two weeks old. After mating, the female will remain pregnant for about 20 days before giving birth to 5-10 young weighing only 3.3 grams each! Within a month after giving birth, Norway lemmings can get pregnant again.

Lemmings are small rodents that belong in the same family as rats, muskrats, hamsters, voles, and more.

In winter, the Norway lemmings can make shelter under the hardpacked snow. Their shelters will start to collapse in the spring causing the lemmings to either move to higher ground with thicker snow or lower ground to spend their summer.