This informative title explores what a den is and the various types that are used or built by animals. Large photographs are used to show the different animals that dwell in dens like bobcats, river otters, Alaska marmots, Arctic wolf pups and more. Each page spread has a simple sentence followed by facts about the animal. The title also includes a comprehension quiz and glossary. SandCastle is an imprint of ABDO Publishing Company.