Once the fungus invades its victim’s body, it’s already too late. The invader spreads through the host in a matter of days. The victim, unaware of what is happening, becomes driven to climb to a high spot. Just before dying, the infected body—a zombie—grasps a perch as the mature fungal invader erupts from the back of the zombie’s head to rain down spores on unsuspecting victims below, starting the cycle again. This isn’t the latest gross-out moment from a George A. Romero horror film; it is part of a very real evolutionary arms race between a parasitic fungus and its victims, ants.
One zombie by itself is not necessarily very scary, but in B movies from, Night of the Living Dead to Zombieland, Hollywood’s animated corpses have a nasty habit of creating more of the walking dead. Controlled by some inexplicable force, perhaps an intensely virulent pathogen, the main preoccupation of a zombie is making other zombies. The story line is pure drive-in movie schlock, yet the popular mythology of zombies has lately been spattered with a coating of biological truth. There actually are organisms that have evolved to control the minds and bodies of other creatures, turning once normal individuals into dazed victims that fulfill the parasite’s need to reproduce itself.