There is one similarity between mice and men. None of us wants to die. Self preservation is one of the strongest instincts in living creatures. And yet high in the Scandinavian mountains lives a small mouselike creature that every few years commits mass suicide. The creatures are called lemmings.

They have given us the phrase, "like lemmings headed for the sea," for that is what they do. Every few years when their population has grown too large and the food supply has become too scarce they leave their burrows and like a mighty army, swarm out of the mountains and rush downward toward the sea. Normally, lemmings fear and avoid water. During their mass march, however, they brave streams and lakes. They also devour everything in their path.

After running for weeks the lemmings finally reac…