Horsehair Worm (also known as Gordian Worm)
Scientific Name: Gordius species (Phylum Nematomorpha)
Order & Family: Order: Gordioidea, Family: Gordiidae
Size: Typically extremely thin (hair-like) and can range from 4 inches to over 14 inches (10-35+ cm) in length.
Natural Habitat
Adults live in freshwater environments like puddles, troughs, streams, and wet soil. Can occasionally be found indoors near water sources (sinks, toilets) or on damp textiles.
Diet & Feeding
Adults do not eat. The larvae are parasitic, feeding on the internal fluids of insects like crickets, grasshoppers, and cockroaches.
Behavior Patterns
Known for their parasitic lifecycle where larvae infect insects and manipulate the host's behavior to seek water; adult worms emerge from the host upon contact with water to breed.
Risks & Benefits
They are harmless to humans, pets, and plants as they cannot parasitize mammals. They are considered beneficial as they help control populations of pest insects like roaches and grasshoppers.
Identified on: 2/18/2026