Do lemmings commit mass suicide?
They must be a Byronic lot, these lemmings, if they really end it all in a watery mass grave as is commonly believed. Fortunately for the lemmings, nature is not that perverse. The legend of the suicidal lemmings is true so far as it goes, but it doesn’t go all the way to a lofty cliff top overlooking the sea.
The lemming — which for the uninitiated is a small Arctic rodent looking a bit like a mouse that needs to see a barber — is an innocuous creature most of the time. Occasionally, though, there is a boom in the population and lemmings begin to disperse away from the epicentre. This is where the wheels start to come off the legend, which has a seething carpet of lemmings ravaging the countryside in their path, when really the lemmings move alone or in small groups. The illusion of a mass movement can be created when the geography leads a them to temporarily bunch up in a dense group before an obstacle.
One such obstacle is water. Lemmings don’t really care for the stuff, but they can swim a good distance in calm conditions if they have to. As they disperse, a lot of lemmings will come to water, head on in if the weather is fine, then be caught out by unforeseen conditions. This leaves a lot of little lemming bodies to wash up on the shore.
A twist is that as the weather changes lemmings that choose not to take the plunge will bunch up along the shore, then turn on their tracks and dissipate. To the casual observer, who sees a heaving mass of lemmings one day, and a lot of dead lemmings washed up the next, an obvious (but wrong) conclusion is that all those lemmings flung themselves recklessly into the water.
The point is that, while lemmings will drown during these dispersals, that isn’t their intention — they just find themselves in the wrong place at the wrong time. Life isn’t easy when you’re the size of a grapefruit, but it isn’t that bad.