UNIVERSITY PARK, Pa., May 9 (UPI) -- A parasitic fungus of ants changes the ants' behavior, creating "zombies" that then die in a spot best suited for the fungus to reproduce, U.S. researchers say.
Researchers at Penn State University said the growing fungus fills the body and head of tropical carpenter ants and affects the ant's central nervous system, creating "zombie" ants that walk in a random manner, unable to find their way home, a university release reported last week.
The ants suffer convulsions, causing them to fall to the ground from their normal spot high in tree canopies. Once on the ground, the ants are unable to find their way back to the canopy and remain at the lower, leafy area which, at about 9 or 10 inches above the soil, is cooler and moister than the canopy, providing ideal conditions for the fungus to thrive.
The fungus then takes over ant behavior, forcing infected ants to bite the main vein on the underside of a leaf, and then causing fibers within the muscles that open and close the ant's mandibles to become detached, causing "lock jaw," which makes an infected ant unable to release the leaf, even after death.
A few days later, the fungus grows through the ant's head and releases spores to be picked up by another wandering ant.
"The fungus attacks the ants on two fronts: first by using the ant as a walking food source, and second by damaging muscle and the ant's central nervous system," David P. Hughes, an assistant professor of entomology and biology, said. "The result for the ant is zombie walking and the death bite, which place the ant in the cool, damp [environment]. Together these events provide the perfect environment for fungal growth and reproduction."
