Wasps are the horror-flick killers of the insect world. Sure, their stingers are scary, but it’s their parasitizing practices that really send a shiver down the exoskeleton.

“They are insects that eat other insects alive,” said Lars Krogmann, an entomologist at the State Museum of Natural History Stuttgart in Germany. “They don’t just kill them, they want to keep them alive for as long as possible.”

Known as parasitoid wasps, these types of wasps are much smaller than the yellow jackets that make people panicky at picnics. With needlelike ovipositors, parasitoid wasps lay their eggs into or on top of other insects. As the young wasps grow, they devour their hosts and eventually kill them, sometimes by bursting through their abdomens like in the movie “Alien.”

Nearly every insect species has at least one species of parasitoid wasp that specializes at murdering it. The emerald cockroach wasp, for example, injects a mind-controlling cocktail into a cockroach’s brain that turns it into a zombie and host for its eggs. Spiders too can fall victim to a hungry wasp larva that forces it to weave webs to protect its cocoon. There are even parasitoid wasps that lay eggs in other parasitoid wasps.