Domestic cats and their wild cousins together comprise the 36 or so species of the Felidae family. Arnold compares their characteristics, including anatomical and behavioral similarities, discusses cats' relationship to people, and—most intriguingly—explains some habits much remarked on by cats' human companions (they're checking their territories on those frequent brief trips outdoors; gifts of dead mice mimic feeding young; and more). As a creature that adopted man, rather than the reverse, the cat offers a chance to observe a ``tame'' animal that acts much like a wild one; by contrasting the two, Arnold has cleverly made both more interesting. The several attractive, well-captioned color photos on each spread, depicting many species, breeds, activities, and stages of growth, make a fine complement. Clear, useful, and appealing. List of species with Latin names, size, range, and endangered status; glossary; index. (Nonfiction. 8-12)