When a group of people is said to be like lemmings, we mean they are acting like a dumb herd and not thinking for themselves. Not just a dumb herd, but a suicidal one, rushing off a cliff to their oblivion. No one wants to be like that – not even lemmings, it turns out.
The bad reputation of lemmings originated in their tendency to have population spikes. When conditions are ripe, huge numbers of lemmings spread across the Scandinavian wilderness. After they eat up all the food in one area, they swarm into new areas.
The definitive public image was shaped by Walt Disney. Soon after their movie Bambi was a huge success they produced a series of feature-length nature documentaries. One of them was titled White Wilderness and starred lemmings. In an infamous scene, the lemmings reach the edge of a precipitous cliff and a voiceover tells us that “this is the last chance to turn back, yet over they go, casting themselves bodily out into space.” Their suicide reputation was effectively cast into stone.
The filmmakers took some liberties, however. They used a different country (Canada) and the wrong kind of lemming; Eskimos were paid $1 for each live lemming but they were brown lemmings instead of Scandinavian ones. And the lemmings did not march voluntarily off the cliff into the sea – a truck dumped them over. Once you know the sequence has been faked, it makes for rather awkward viewing. Several of the brown lemmings pause at the edge. One or two look like they are trying to turn back. They don’t want to be there at all. They don’t want to jump. It looks less like suicide and more like murder. They may just be rodents but they are not stupid. Think about that the next time someone says you are acting just like a lemming.