Here's a fun fact I just learned!
It's fairly well known nowadays that lemmings do not, in fact, follow one another off cliffs to their deaths. The myth has been persistent for many years, and was notably perpetuated by Disney in their documentary White Wilderness, which showed lemmings apparently diving from a cliff to their deaths. Truly though, these lemmings had been flown half way across the world and were thrown from the cliffs by the documentary's producers.