There's a fungus that turns ants into "zombies" - Apparently.
Ophiocordyceps unilateralis, a fungus that infects carpenter ants, takes control of the ant's body and eventually kills it. But before that, the fungus causes the ant to climb to a high location and bite onto a leaf, creating a perfect environment for the fungus to produce fruiting bodies and disperse its spores. This fungus has been observed in the rainforests of South America, and its control over the ants' behavior has been extensively studied by scientists.