From The Loom:
At the Loom we believe that the path to wisdom runs through the Land of Gross. We do not show you pictures of worms crawling out of frog noses merely to ruin your lunch. We do not urge you to check out these freaky videos of worms crawling out of frog mouths and fish gills merely to give you something to talk about at the high school cafeteria table tomorrow (Dude, you totally will not believe what I saw…) These images have something profound to say.
The worm in question is the gordian worm or horsehair worm, Paragordius tricuspidatus. It has become famous in recent months for its powers of manipulation. The gordian worm lives as an adult in the water, where they form orgiastic knots. They lay eggs at the edge of the water, which can only mature if they’re ingested by insects such as crickets. The worms feed on the inner juices of the crickets until they fill up the entire body cavity. In order to get back to the water, the gordian worms cause their hosts hurl themselves into ponds or streams. As the insects die, the worms slither out to find the nearest mating knot.
More here.