Horsehair Worm
Scientific Name: Gordius species
Order & Family: Order: Gordiida, Family: Gordiidae
Size: Typically 4 inches to 14 inches long (10–35 cm), but very thin (about 1 mm diameter).
Natural Habitat
Found in fresh water sources like ponds, streams, puddles, and water troughs; adults are aquatic, while larvae are internal parasites of insects.
Diet & Feeding
Larvae are parasites that absorb nutrients through their body wall from the host's fluid; adults do not feed.
Behavior Patterns
They are famous for 'mind control'—the larva develops inside a host (like a cricket or beetle) and eventually manipulates the host to jump into water, where the adult worm emerges to mate.
Risks & Benefits
They pose no risk to humans, pets, or plants; they are considered beneficial to ecosystems as they help regulate populations of crickets, grasshoppers, and beetles.
Identified on: 3/12/2026