Weasels have a bad reputation among bird farmers and have been cast as literal villains in books and cartoons, but they can actually help control vermin populations -- and ferrets can make great pets. Learn more about various types of weasels (including why they dance) in today's episode of BrainStuff, based on these articles: https://animals.howstuffworks.com/mammals/weasels.htm; https://animals.howstuffworks.com/pets/otherpets/ferrets.htm