Why do lemmings commit mass suicide?
–Elizabeth Hoyt, Arvada, Colorado The lemming’s legendary compulsion for communal self-destruction, so widely believed that it has become a metaphor for pack behavior run amok, is pure fiction. What is fact is that these busy breeders go through roller-coaster-like cycles of population booms and busts on the order of two or three times a decade. In peak years, aptly called “lemming years,” their numbers reach such epic proportions that they literally eat themselves out of house and home. The periodic floods of lemmings onto the tundra after seasons of prolific procreation earned them the Inuit name kilangmiutak, or “one who comes from the sky.” At such times, they can multiply a thousandfold, and when they undertake their normal migrations, make rush-hour commuting seem positively breezy. But they’re not on some orchestrated death march to the sea, fleeing overcrowding or claustrophobia. More likely, researchers believe, the rodents are simply seeking greener seasonal pastures and en
