A beaver can fell up to 300 trees in a year! They are some of nature's greatest builders and are considered a "keystone species" for the ways they benefit the environment. However, many people see beavers as mischief makers because their dams can cause flooding and property damage. This book introduces readers to fun facts about beavers, from their amazing swimming ability to their strong, orange teeth. Critical thinking is encouraged as readers learn about how beavers help their environment and sometimes cause destruction. Fascinating text is paired with exciting photographs to give readers a deep understanding of the busy beaver.