Horsehair Worm

Scientific Name: Gordius sp. (Gordiacea)

Order & Family: Order: Gordiida, Family: Gordiidae

Size: Typically 10 to 35 centimeters long, but very thin (about 1 to 3 millimeters in diameter).

Horsehair Worm

Natural Habitat

Found in damp environments, puddles, pools, streams, and cisterns; larvae are internal parasites of insects.

Diet & Feeding

Larvae are parasites that absorb nutrients from the body cavity of hosts like crickets and grasshoppers; adults do not eat.

Behavior Patterns

Adults are free-living in water and often knot themselves together (Gordian knots) during mating. They manipulate the host's behavior to seek water once the worm is ready to emerge.

Risks & Benefits

Harmless to humans, livestock, and plants. They are considered beneficial to ecosystems as they help control populations of insects like crickets and beetles.

Identified on: 3/12/2026