Scientists have discovered that the parasitic jewel wasp injects venom directly into a cockroach’s brain to incapacitate the roach. The venom blocks a chemical that controls the victim’s free will to walk, among other things.
When the roach becomes a “zombie”, it is taken back to the wasp’s lair. There, the wasp lays an egg in the roach’s abdomen. When the larva hatches, it eats the immobile but still living roach from the inside out.
The young wasp continues to feed on the roach’s insides until a month later, at which time it emerges from the roach as a mature wasp.