Lemmings don’t jump off cliffs, but they do two things that started the legend:
1. They migrate if the population density gets too high. This ensures they don’t eat out all the plants in an area, and spreads them out to areas with thin or no lemming population.
2. When migrating, they will attempt to swim bodies of water that are in their way, even if they cannot see the other side. They can swim much further than they can see, and arctic Siberia where they evolved has many rivers, so they have to swim to get far enough to thin out the population. So when their migration brings them to a lake or sea shore, they’ll go up and down the shore a while to see if they can go around it without deviating too much from their original direction. But when that doesn’t work and more and more migrating lemmings keep arriving in the same area, eventually they jump in and swim. Maybe there’s an opposite shore within reach…
Lemmings don’t jump off cliffs, but they do two things that started the legend:
1. They migrate if the population density gets too high. This ensures they don’t eat out all the plants in an area, and spreads them out to areas with thin or no lemming population.
2. When migrating, they will attempt to swim bodies of water that are in their way, even if they cannot see the other side. They can swim much further than they can see, and arctic Siberia where they evolved has many rivers, so they have to swim to get far enough to thin out the population. So when their migration brings them to a lake or sea shore, they’ll go up and down the shore a while to see if they can go around it without deviating too much from their original direction. But when that doesn’t work and more and more migrating lemmings keep arriving in the same area, eventually they jump in and swim. Maybe there’s an opposite shore within reach…