Biting flies feed on blood, attacking humans and other animals as food sources. Some are capable of transferring disease through these feeding habits. There are many species of biting flies, each with its own habits and ecology.
Biting midges are biting flies commonly found near the coast. Adult sand flies measure only 1 to 3 mm in length and are capable of fitting through fine, mesh screens. They breed in salt marsh areas. Larvae thrive in mud and can sometimes be seen swimming freely in infested waters. Larval biting midges pupate at the water’s edge or on floating sticks and leaves. Biting midges are susceptible to air currents and emerge most commonly on still days.
Black flies generally make their homes in most parts of the United States, but are a particular nuisance in the northern part of America. Black flies are most active during the day and are often found near moving water. They will feed on humans and animals.
Due to their large size and the intensity of their bite, horse fly bites are often considered one of the most painful.