The parasitic worm seeks out bodies of water with its antennae, which pick up the slightest changes in humidity. Then, seemingly against its better judgment, the host proceeds to perform a sicknasty cannonball: “If you take a cricket that actually has a worm in it,” said Hanelt, “and put it next to the water, it will always, in every case, jump immediately in.”
After admiring the cannonball, the worm, monitoring the world through a porthole it bored in the cricket, makes its move, squirming out of its host as soon as it hits the water. In nature, it’s typically one worm per cricket, though every now and then two or three will emerge. In Hanelt’s lab, however, his record is an astonishing 32 worms erupting from one unfortunate host (that GIF at top, which I ain’t even about to apologize for, was half that many worms).
The parasite, now free, will swim around in search of a mate. When they pair up, the male aligns his cloaca with the female and passes his sperm. Having served his sole earthly purpose, he will die. The female goes on to lay as many as 15 million eggs, which she pastes underwater on a stick or stone. When she’s done, she too will die, emptied of eggs and totally flattened out like a straw wrapper that’s lost its straw. Two weeks later, her eggs hatch into the larvae that settle once more onto the river bottom, beginning the process anew.