Birds, spiders, and other insects all like to eat caterpillars. But some kinds of caterpillars face a scarier threat: predators that take control of them! Readers learn all about parasites, specifically those that make zombies out of their caterpillar prey. Full-color photographs show these parasites in action, from the gross emergence of wasp larvae to the disgusting liquefaction of dead caterpillars by a nasty virus. Fascinating fact boxes engage readers with a host of details fit for a horror movie–even though they could happen right in your backyard!