Ophiocordyceps unilateralis, a parasitic fungus, effectively turns ants into zombies. The fungus compels the ant to bite onto the underside of a low-hanging leaf where it dies, and the fungus then sends a fruiting body out through the ant’s head to disseminate spores. – WTF Fun Facts
Source: Cordyceps zombie fungus takes over ants’ bodies (nationalgeographic.com)