An Australian wasp provides an important service to humans, researchers report: It paralyzes a poisonous spider, the redback.

Although female wasps sting and paralyze the spiders, they don’t kill them, said Andrew Austin, an evolutionary biologist at the University of Adelaide in Australia and an author of a new study on the wasp in The Australian Journal of Entomology.

“The female wasp drags the spider back to a crevice or burrow,” he said. “She lays an egg on it and when the egg hatches, the wasp larvae have a fresh spider to feed on.”