Lemmings do not intentionally hurl themselves into the sea. It’s a myth. Yes, the northern rodents have experienced periodic population booms, prompting them to migrate en masse to new territory, sometimes drowning or being trampled along the way. But not deliberately. The lemming, like every other animal, tends to prefer being alive.
Apparently, the myth took hold with the 1958 Disney documentary “White Wilderness.” Instead of shooting an actual migration, the filmmakers took it upon themselves to transport a few dozen lemmings to a riverbank in Alberta, Canada, a landlocked province where the animals are not native. They then tossed the rodents off a cliff into the “sea” and filmed them as they drowned, thus propagating a persistent urban legend. For its efforts, the allegedly pro-rodent studio won an Oscar for Best Documentary.