|Stalk growing from dead ant's head|
Ophiocordyceps unilateralis is a fungus that infects ants, hijacks the body, and uses it to find an ideal spot to spread spores. The parasite fungus can infect and kill off entire colonies of ant.
Ants have adapted though. When they see a friend behaving strangely or staggering, they avoid an ant zombie apocalypse by carrying the infected one away from the colony.
Pretty wicked, huh?