There's a fungus that turns ants into "zombies" - Apparently.
The fungus Ophiocordyceps unilateralis infects ants in the rainforests of South America, taking control of their bodies and causing them to climb to high locations before producing spores that can spread the fungus. Infected ants, which are often called "zombie ants," have been found to be 100% controlled by the fungus, which even causes them to bite onto a leaf before dying. This fungus has been studied extensively by mycologists, who have found it to be a fascinating example of mind control in the natural world.