A flying insect plaguing areas near the Rock River are actually a good thing.

UW-Whitewater at Rock County Biology Professor Tom Klubertanz says they are net-spinning caddisflies.

Klubertanz says while it may be annoying to drive through a cloud of them, they are good for the environment.

Klubertanz says the caddisflies clean up the river by eating sediment, and are a source of food for fish, certain birds, and bats.

Klubertanz says the caddisflies are attracted to light, so turning off outdoor lights will help keep them at bay.