Why Do Lemmings Go on a Death March?

Lemmings are small rodents, only 4 – 5 inches long, that live in most Arctic and Subarctic regions of the world. Legend has made them famous for their death plunge into the sea.

In Norway and other Scandinavian countries, large numbers of these animals make periodic migrations from their mountain homes, eating everything edible in their path, until they reach the sea, where they plunge in and are finally drowned.

Scientists are not absolutely certain why this mass death plunge takes place, but they think that every three or four years, the feeding grounds of the lemmings in the higher regions become overcrowded.

Thus the lemmings are forced to migrate in search of food. They seem to take a direct path to the sea, swimming across lakes and streams on their way.

When they finally do reach the ocean, these land animals do not stop, but instead, begin to swim out to sea.

Although the reasons for this final action are not known, one possibility is that the animals think the ocean is just another stream or small body of water to be crossed, and do not realize this swim will be their last.