You may know them as Alvin’s little friends who love to sing in the movie Alvin and the Chipmunks, but in reality, chipmunks really love to chirp and use their harmony to communicate with each other.

— Cora Wieneke, Mount Horeb, Wis. A Erin Flynn, conservation education curator at Henry Vilas Zoo in Madison, Wis.: Squirrels, beavers, chipmunks and rabbits all have similarly shaped teeth because ...