Includes bibliographical references

"What makes a frog an amphibian but a snake a reptile? Although they share some characteristics, these two animal classes are different and are often confused. What kind of skin covering do the animals have? How do they stay warm? How do they get the oxygen they need to breathe? How are they born? Following in the footsteps of Polar Bears and Penguins, Clouds, and Trees, this latest in Arbordale's Compare and Contrast series has children pondering the similarities and differences between the two animal classes through stunning photographs and simple, non-fiction text"--,Provided by publisher