There's a fungus that turns ants into "zombies" - Apparently.
Ophiocordyceps unilateralis, a fungus, infects carpenter ants, eventually killing them. However, before dying, the fungus takes control of the ant's body, causing it 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 essentially turns the ants into "zombies" to facilitate its own reproduction, a process that can take up to 8 days.