Once it infects an ant, the fungus uses as-yet-unidentified chemicals to control the ant's behavior, [study researcher David] Hughes told LiveScience. It directs the ant to leave its colony (a very un-ant-like thing to do) and bite down on the underside of a leaf -- the ant's soon-to-be resting place. Once it is killed by the fungus, the ant remains anchored in place, thanks to its death grip on the leaf.
Ultimately, the fungus produces a long stalk that protrudes from the ant's head, shooting spores out in the hopes of infecting other ants. Two of the four newly discovered species also sprouted smaller stalks elsewhere, including from the victim's feet and lower leg joints - the equivalent of knees.