In nature, parasites are only out for themselves, often to the detriment of their host. This fascinating book puts the spotlight on some of the nastier organisms in nature--like the louse that lives in a fish's mouth! Readers will discover through the inviting, at-level text that parasitic behavior is just a part of life, one of the necessary adaptations that help certain creatures survive in the wild. They'll love this volume's colorful photographs and fact boxes that highlight more interesting information.