Considering this True Facts video is about beavers, Ze Frank plows through it with an astonishing lack of sexual innuendo. It's still got jokes, and it's still quite interesting. Beavers are rodents, but you'd never know it by their behavior. They swim, eat trees, and build dams. Here we find out why and how they do those things, which includes taking a deep dive into the structure and composition of teeth. I now know more about horses' teeth because I watched a video about beavers.