Horsehair worm

Scientific Name: Gordius aquaticus

Order & Family: Order: Gordiida; Family: Gordiidae

Size: 10 to 35 centimeters long (4 to 14 inches), but very thin

Bodies of water like streams, ponds, puddles, and sometimes water bowls or swimming pools

Larvae are parasites of insects (crickets, grasshoppers, beetles); adults do not eat and live only to reproduce

Larvae develop inside a host insect and influence its behavior to seek water; once the host reaches water, the adult worm emerges to mate

Harmless to humans, pets, and plants; they help control populations of some insects like crickets and grasshoppers

Identified on: 2/17/2026