Hair Worms: Nematomorpha

Hair worms are long and thin—2 to 118 inches (5 to 300 centimeters) long and 0.02 to 0.4 inch (0.5 to 10 millimeters) wide. They are black, brown, yellow, white, or gray. The front end of most of these worms has a white tip with a thin dark band behind it. Some hair worms have raised bumps on their surface. Young hair worms are parasites (PAIR-eh-sites) and live on or in other animals, or hosts, without helping them and usually harming them, but adults live freely.