It is rare to come across a worm that stings outside of tropical regions, but if you do, chances are it is a bristle worm. Bristle worms may release “poison” when it stings, but the poison is not harmful to humans, only other very small animals.

Large bristle worms are usually gray or brownish in color. Some are also salmon pink with white setae around the body. Like most worms, bristle worms are nocturnal, so they are not usually around during the day.