Toe biter
Several species within the belostomatidae family are referred to as toe biters. Most are tan or brown, measuring up to 2.5 inches in length. They await their prey at the bottom of streams and don't take being stepped on very lightly, thus, their name. When removed from the water, they can "play dead" but still render a nasty bite to protect itself. Toe biters are able to fly and may congregate at bright lights.
Backswimmers
Although just .5 inches long, backswimmers can deliver a bite resembling a bee sting. They inhabit almost any type of freshwater but prefer slow-moving or stagnant water. They swim on their backs and are black and white. Backswimmers can fly and are sometimes attracted to swimming pools that are lighted at night.
Dobsonfly
The larvae inhabit fast-moving freshwater and are often used as bait by fly fishermen. Although the larvae only grow to 3 inches in length, their sharp mandibles cause a painful bite. Larvae are light brown and resemble flattened caterpillars with white tufts along their sides. Adults do not live in the water.
Predaceous Diving Beetle
Both the adults and young can bite. The adults are black and shiny and less than 1.5 inches in length. Growing up to 2 inches in length, the larvae resemble tiny elongated shrimp and are well-camouflaged. Both adults and larvae spend their time below the water surface and prefer to hide rather than bite when disturbed.