They readily approach humans to feed on the mosquitoes and biting flies that humans attract.

Suggested functions include crypsis, forms of motion camouflage, social signaling and recognition, and discouraging biting flies.

A 2012 study suggests that stripes may have developed to discourage biting flies.

Experienced anglers find fishing best when the biting flies which breed in cold, clean water are most numerous.

Biting flies feed during daylight hours only and tend to zero in on areas of thinner skin, such as the nape of the neck or ears and ankles.