Horsehair Worm
Scientific Name: Nematomorpha
Order & Family: Phylum Nematomorpha, various orders and families
Size: Typically 10 to 35 centimeters (4 to 14 inches) long, but very thin (about 1 to 3 millimeters).
Natural Habitat
Often found in puddles, swimming pools, livestock troughs, and near moist soil after emerging from hosts.
Diet & Feeding
Larvae are internal parasites of insects (like crickets, beetles, and cockroaches); adults do not eat as they lack functional digestive tracts.
Behavior Patterns
The larvae develop inside an insect host. When mature, they influence the host to seek water. Once the host enters water, the adult worm emerges to mate and lay eggs.
Risks & Benefits
They are harmless to humans, pets, and plants. They are beneficial for the ecosystem as they help control populations of insects like crickets and grasshoppers.
Identified on: 6/6/2026