Horsehair Worms or Gordian worms is a common name used for parasitic animals of phylum Nematomorpha. They are found in damp areas such as watering troughs, streams, puddles, and cisterns. Most species have a body length ranging from 50 to 100 centimeters and body diameter from 1 to 3 millimeters. In extreme cases they can even reach up to 2 meters long. The adult worms are free living, but the larvae are parasitic on beetles, cockroaches, orthopterans, and crustaceans.