Like Lemmings: The lemming gets its name from the Norwegian word for "destroying," because of its voracious migrations. But the one thing you think you know about lemmings is not true. Overpopulation does not cause them to fling themselves, en masse, from cliffs. The myth of suicidal lemmings owes a lot to a 1958 Disney documentary "White Wilderness," in which a lemming migration (and mass suicide) was faked in Alberta, which is distinctly non-lemming territory.