Art, No-see-ums are any species of biting midges (gnats or "punkies"). They are not actually invisible, just small, about 2 mm long. Mosquito netting usually just barely keeps them out. They swarm in swampy areas with no wind, flying into your eyes, ears and mouth. And they bite! Camping with no-see-ums is misery! The only thing I've ever found to stop them is Avon Skin-So-Soft. Ordinary Off is useless but I expect the new Skintastic would work.