Beginning with their anatomy, Hutson explores how bats' unique characteristics have enabled them to evolve to fill a wide variety of habitats and niches. He examines their different life cycles, dietary strategies, migration patterns, and unique feats of echolocation. And he also discusses their predators, parasites, the man-made threats to their ecosystem, and how the viruses harbored by bats can have an impact on humans.

Bats also features an appendix of bat families that details the number of genera and species and their distribution and diet.