The fungus, a species of Ophiocordyceps, targets carpenter ants living high in Thailand's rain forest canopy. In a study, researchers used microscopes to peer inside affected ants and see how the infection progresses. The team found that the growing fungus slowly fills the ant's body and head, causing muscles to waste away and muscle fibers to spread apart.

It takes about three to nine days from initial infection for the ants to become completely zombified, the team found. At first, the infected ants go about their normal business, residing in their nests, interacting with other ants, and even feeding. The work also found that the fungus tends to kill its ant hosts at high noon, although the exact reason for this timing remains a mystery.