No-See-ums (Family Ceratopogonidae)
WHAT IS A NO-SEE-UM?   No-see-ums are tiny biting flies that often live near water. You often see many of them swarming together in a cloud. Keep your mouth shut or you might breathe some in or swallow them! (It won’t hurt you, but it will probably make you cough.)   Biting midges are called no-see-ums because they’re so tiny that it is hard to see ‘um. No-see-ums are less than ¼ of an inch long.
WHERE DO NO-SEE-UMS LIVE? They often stay in shrubs or the thick layer of dead leaves that naturally covers the ground. Scrubbing your feet around in the leaves is a good way to get them stirred up. Don’t do it!   Most no-see-ums never fly more than 350 feet from their breeding area, so if they’re bothering you, you might be able to get away from them by moving a few yards
WHY DO NO-SEE-UMS BITE?   Only the females bite and suck blood. They need the protein in this blood to make their eggs. No-see-ums will take blood from mammals, birds, and reptiles. Male no-see-ums are nectar feeders and do not bite. While the bite is not painful, it becomes very itchy. Some people get a red spot 1-2 inches wide! Try not to scratch the bites; it makes them itch longer and can make the bites get infected. No-see-um larvae (babies) can be found in water, mud, or moist dead leaves. They especially like to live in the dying plants along the edge of a salt marsh. The larvae eat dead plant and animal matter. 

HOW CAN YOU AVOID NO-SEE-UM BITES? The best way to avoid getting bitten by no-see-ums is to wear insect repellent when you are outside in the spring, summer, and fall. Also, move quickly away from the areas where they’re swarming. If you get far enough away, they won’t follow you.