Source: Wired Motherboard
More commonly known as the horsehair worms, because folks with a limited understanding of reality once thought they were horsehairs that animated upon hitting water, the 350 or so known species invade insects like the luckless cricket above. After developing for several months, the worms mind-control their hosts to make a kamikaze dive into water, then escape through holes bored in the insect’s exoskeleton. The parasites end up in a tangled knot that can be as heavy as the tattered—and oftentimes very much alive—host they leave behind.
“I always tell students this way to think about it,” said Hanelt. “Imagine if I told you to walk over to your car and remove half of its weight, but still have the car be able to get you to the airport. And somehow these worms have figured out how to do that within the cricket host, that they’re able to take half of everything that’s within that cricket but still make it tick. It’s kind of amazing.”