The author-illustrator of several outstanding science books (Urban Roosts, 1990) brings her sensitivity to natural history and design to the life cycle of a common North American bat. An artist's eye is apparent in each dramatic spread here—velvety black bats swooping against blue-black skies, with text and moon glowing in silver-white; rough-grained barn beams drawing the eye to a life-sized bat with a naked pink pup clinging to her fur; hibernating bats clustered near the ceiling of a gray cave. In her brief text, Bash describes the bats' birth and migration and explains how they use echolocation to find prey. A final section shows some unique bat noses and ears, the hopping movement of the vampire bat, and a bat house that readers can make. Beautiful and informative. (Nonfiction. 7-10)