This addition to Gibbons extensive shelf of topic books draws young readers into the world of alligators and crocodiles by first asking readers to distinguish between them. She describes the physical similarities and differences between the two most common species of the worlds largest reptiles, as well as their habitats, habits, prey, locomotion, senses, communication, mating and nesting behavior, and status as endangered species. The author has chosen facts that will engage her readers, organized the information logically, and presented it in straightforward exposition. Pen-and-ink and watercolor illustrations show both species in their likely environment. Labels are plentiful and unfamiliar terms are explained in context.