If a bumblebee is attacked by a thick-headed fly, it’s doomed. The fly will lay an egg inside it and the larva will eat it alive. And if that wasn’t an ignoble enough fate, the larva also forces the bee to burrow into the ground. The soil is warm and safe, and makes for a better nursery for the developing fly. And the bee? The bee is as good as dead. For its last act, it might as well dig its own grave.

There are around 800 species of thick-headed flies or conopids, and they’re all parasites. They use the hard tips of their abdomens like can-openers to prise apart the body segments of bees and wasps, so they