What is a Lemming and Do They Commit Suicide?

Do These Small Rodents Follow Each Other Over Cliffs to Their Death?

Aug 14, 2009

Lemmings have been the subject of computer games, comics and various jokes due to the belief that they participate in mass suicides.

It is a common belief that lemmings commit suicide. This belief came about due to the fact that lemming populations fluctuate widely and partially due to a Disney documentary that later proved to have been faked.

What are Lemmings?

Lemmings are small rodents that live in the Arctic Tundra and Scandinavia. There are four genera of lemmings; Collared Lemmings, True or Norwegian Lemmings, Wood or Red-Backed Lemmings and Bog Lemmings. The Current Taxonomy of the Lemming:

Lemmings breed throughout the year and gestation is only twenty-one days. Breeding is more prevalent in summer and young born at this time are weaned within two weeks and are able to reproduce by the end of the season.

All this contributes to population density. Due to their high numbers, lemmings tend to use up their resources quickly and thus are forced to migrate to new habitats for space and food.

Lemming Suicide – Fact or Fiction?

Lemming populations have regular fluctuations. The numbers can increase greatly and then drop to near extinction, and this can happen every three to four years. It is not fully understood why they fluctuate so much, but theories put forth are due to changes in climate, food resources, predators, overcrowding stress, and infectious diseases.

Mass migration of lemmings can result in deaths, but it is not suicide. While they prefer to take paths whilst migrating, often lemmings must cross streams and small lakes. Unfortunately they are unable to distinguish between small lakes and large lakes or the sea and thus drown. Lemmings can swim, but only for approximately 200 meters.

Lemmings are also prey for multiple carnivorous mammals and birds, so deaths from predators would be a factor during migration also.

Where the Lemming Suicide Myth Started

In 1958 Disney released a nature documentary called White Wilderness in which they filmed a fake migration sequence with imported collared lemmings. They placed lemmings on a spinning turntable, which was filmed from different angles. They then herded the lemmings off a small cliff and into a river.

This would make for a more interesting movie but we know now that lemmings don’t commit suicide, they simply migrate and have large fluctuations in their population.

Hickman, Roberts, Larson & I’Anson, 2004, 'Mammels’, in Integrated Principles of Zoology, McGraw Hill Inc.,New York, chapter 28.

Kruszelnicki, K, 2004, ‘Lemming Suicide’ in Great Myth Conceptions, ed. Harper Collins Publishers, Sydney, NSW.

The copyright of the article What is a Lemming and Do They Commit Suicide? in Mammals is owned by Roberta Goli. Permission to republish What is a Lemming and Do They Commit Suicide? in print or online must be granted by the author in writing.