Adult no-see-ums are about 1/16 inch long and look like a smaller version of the mosquito. They commonly breed along the edges of moist areas, such as ponds, marshes or areas of standing water in your yard. The eggs are laid in the soil and hatch into wormlike larvae in about three days. As larvae, they feed on organic matter in a state of decomposition before pupating. Once they become adults, they are busy feeding and mating.