Horsehair worm

Found in damp areas such as ponds, streams, puddles, and gardens after rain; often emerges from insects.

As larvae, they are internal parasites of arthropods (like crickets and beetles); as adults, they do not eat—their primary purpose is mating.

Larvae develop inside a host's body. Once mature, they manipulate the host's behavior to seek water, where the worm then emerges and the host usually dies.

They are completely harmless to humans, pets, and plants. They are beneficial to ecosystems as natural population controllers for insects like crickets and grasshoppers.