Horsehair worm

Horsehair worm, hair snake, or hairworm, any of about 200 types of long, thin worms making up the phylum Nematomorpha. They may grow to 28 in (70 cm). The young are hatched from eggs and form cysts, which may be eaten by insects. The larva then leave the cysts and live in the insects as parasites. The worms leave the insects' bodies when they reach adulthood.