Horsehair Worm

Scientific Name: Gordius sp. (part of Phylum Nematomorpha)

Order & Family: Order: Gordioidea; Family: Gordiidae

Size: Typically 10 to 100 cm (4 to 40 inches) in length, but extremely thin (1-3 mm diameter).

Horsehair Worm

Natural Habitat

Adults live in water sources like puddles, troughs, streams, and swimming pools. Larvae are internal parasites of insects like crickets, grasshoppers, and beetles.

Diet & Feeding

Adults do not feed; they live off stored energy. Larvae are parasitic and absorb nutrients from the body fluids of their insect hosts.

Behavior Patterns

They are famous for zombifying their host insects, chemically compelling them to seek water so the adult worm can burst out and reproduce. They often twist themselves into intricate knots, earning them the nickname 'Gordian worms'.

Risks & Benefits

Harmless to humans, pets, and plants; they cannot infect mammals. They are generally considered beneficial as they help control populations of pest insects like roaches and grasshoppers.

Identified on: 3/4/2026