A long slender worm related to the nematodes, the larvae being parasites of arthropods and the adults living in water or damp soil.
Phylum Nematomorpha: two classes
 Example sentencesExamples
-  The good news is horsehair worms are internal parasites of insects only and do not harm humans, animals or plants.
 -  No control is necessary for horsehair worms found outside or inside and they should just be ignored.
 -  Locomotion of adult horsehair worms is a slow whipping action; males are more active than females.
 -  These are the horsehair worms or Nematomorpha and the Gastrotricha.
 -  Once the host enters the water, the horsehair worm breaks through the body wall of the host.