There's a fungus that turns ants into "zombies" - Apparently.
Ophiocordyceps unilateralis, a fungus found in the rainforests of South America, infects carpenter ants and takes control of their bodies. The fungus grows inside the ant's head, eventually killing it, and causes the ant to climb to a high location where the fungus can produce fruiting bodies and disperse its spores. This process is often referred to as "zombie ants" due to the fungus's mind-controlling effects on the ant's behavior. This fungus was first described in 1919 by a British mycologist.