Parasitic hairworm (horsehair worm)

Adults occur in freshwater, including ponds, puddles, streams, and water containers. Juveniles develop inside terrestrial insects, especially crickets and grasshoppers.

Adults generally do not feed, relying on stored energy. Larvae absorb nutrients from their insect hosts.

Larvae parasitize insects and manipulate infected hosts into entering water, where the worms emerge, mate, and reproduce. Adults are free-living and harmless.

Not dangerous to people, pets, plants, or fish, and they do not parasitize humans. They help regulate cricket and grasshopper populations and indicate freshwater presence.