Dragonflies are prominent inhabitants of lakes and ponds. The nymphs are large and often occur in great numbers. Dragonflies are predacious in both the adult and nymph forms and are the top of the insect food chain where they occur. They crawl around on under water structure and hunt from ambush, utilizing a hinged grabber located on the under side of head to capture prey. They are large and tasty to game fish including trout and bass.

Some species of Dragon Fly nymphs live and hunt through the leaf matter and mud of the bottom sediments. They are lethargic and well camouflaged. These types of dragon flies live in most lakes but may be the most important type in high mountain lakes.