The world of animals is a source of constant fascination for young learners; teach them about the various amazing ways each of the six major animal groups' changes throughout their lifetime. Animals covered are frogs, fish, mice, and more as children learn about the differences between animal classes; live birth or eggs? Hair or scales? Hibernation or another adaptation? Worksheets and informational sheets convey information in an interesting and easy-to-understand fashion. 96 classroom reproducible pages, softcover; answer key included. Grades 2-3.