When young Randy the rat overhears Forrest the frog grumbling about mammals, Randy sets out on a mission to find out what exactly a mammal is. After interviewing other animals in the forest and learning about the characteristics of mammals, Randy realizes that he too is a mammal! The humorous narrative and dialogue will draw elementary-aged readers into this brightly illustrated life science lesson about animal diversity and classification. Includes fact page, glossary, and resources for further research.