Don't you just hate mind-controlling parasites? They might be my least favorite aspect of the animal kingdom, especially ones that mess with awesome bugs like the praying mantis. Sadly, these villainous, vile creatures are very real, and they are truly terrifying.
Horsehair worms, the most common of these parasites, hitch a ride into their host — usually bugs like beetles, cockroaches, or mantises — through infected water. Then, when the time is right, they hijack the brain of their host and force it to drown itself. This is so the worm can return to water to breed.
Sometimes, though, that doesn't always work out, as you can see in the video below. WARNING! This is not for the squeamish.
This just makes me afraid of everything now. How long until these worms evolve with the capability of controlling human minds and making us drown ourselves!? I don't even want to think about that.