"Beavers are remarkable animals. They have teeth that self-sharpen and never stop growing, a heart that can slow down, and valves in their ears and noses that close when they dive. Their tail is the most multi-purpose of any animal on this planet; in addition to communication, its many functions include serving as an air conditioner in summer and a food pantry in winter. Also, few animals are so famous--or infamous--because only humans have a greater...