When people refer to sand flies in North America, they might use several names, such as no-see-ums, punkies, biting midges or black gnats. They are called sand flies because they often are found on beaches and along waterways when temperatures are warm. Many species inflict a painful bite and some can transmit diseases.
These flies are found near water so the females can lay their eggs in damp soil or in the water. Adult sand fly activity begins in early spring and subsides by late June. However, in very warm climates like Florida and South Texas, activity can continue all year. Steady breezes keep these insects at bay and bug repellent may also prove effective. However, entering the water may lessen the strength of repellents.