At this very moment, in a corner of your backyard, dozens of wasp larvae may be burrowing through the insides of a caterpillar. After chewing holes in its exoskeleton, these larvae build cocoons on the caterpillar's back so they can grow into adults while still feeding off their host.
Such parasitism is more common than you think. Some of the most blood-curling forms of parasitism can transform the host — whether ant, beetle or caterpillar — into a zombie-like puppet that acts according to the whims of the parasite.
