Invasion of the body snatchers
It's the title of a science fiction horror film, but it's also a real occurrence for certain insects. In this video (another LinkedIn find) from the BBC, we meet cordyceps, a fungal infection that controls and eventually kills ants. This is a 3 minute clip from the longer Planet Earth series. If you've never seen this remarkable series, I highly recommend it. Not only do I enjoy it, I've found that even my pets enjoy it, too (yeah, I know, that's silly).