Before they appeared in movies, zombies played an important role in voodoo (or vodoun) culture in West Africa and Haiti. The word probably comes from nzambi, which roughly translates to, “spirit of a dead person.” Zombies are humans without a soul. In the early 1980s, ethnobotanist Wade Davis proposed that zombies were more than mere witchcraft and folklore, and that zombie powder found in Haitian ceremonies might be derived from tetrodotoxin, a powerful neurotoxin that blocks nerve channels.
Davis drew his hypothesis partially from real-world examples such as the female jewel wasp (pictured), which injects its tetrodotoxin into a cockroach’s brain, shutting down the roach’s fight-or-flight response. The wasp then leads the drugged bug into its burrow, lays its eggs upon the cockroach’s abdomen and, eight days later, the larvae hatch and feed upon the roach, burrowing into its innards. The cockroach is alive throughout and under the wasp’s control.