Why do lemmings jump off cliffs

Q. Where did the myth come from

A. Lemmings do seem to perform mass migrations periodically and, since they normally inhabit low lying areas, if a large group find themselves gathered at the top of a cliff, they will instinctively jump over the edge. However lemmings are quite good swimmers and usually make it back to dry land.

However, it's thought that infamous footage of lemmings hurling themselves from a cliff in a nature documentary called 'White Wilderness' in 1958 was only possible because a camera crewmember 'encouraged' these small mammals over the edge.

But, contrary to legend, neither hunger nor any population-control mechanism drives them over the edge.

Q. Why do lemmings migrate then

A. Biologists were keen to account for the reasoning behind sharp rises and subsequent falls in lemming population numbers. One possible, though flawed explanation, was that in times of need groups of lemmings would sacrifice themselves by performing mass migrations to pastures new.

Q. Why flawed

A. Although biologists originally favoured the migrate to survive theory to explain lemming's migration tendencies the migration patterns do not correlate with periods of food shortage.

So the mystery of why lemmings migrate remains.

Q. What are lemmings exactly

A. Lemmings are rodents that are closely related to voles and meadow mice.

Q. Where do lemmings live

A. In the northern hemisphere, even as far up as the Arctic. Unlike most mammals that spend winter in the Arctic, lemmings don't hibernate.

Looking for clarification on a natural myth

by Lisa Cardy