Mayflies are also called shadflies and lake flies. They are aquatic insects. They are attracted to light. They become a nuisance to people when they gather at night near doorways of homes and businesses. They sometimes gather in large numbers. Mayflies are members of the insect order Ephemeroptera.
They have two pair of wings, so they are not related to houseflies or other true flies. Flies have only one pair of wings. There are many species of mayflies. They are very slender insects. Some mayflies are very small – one thirty-seconds of an inch long. Others are longer – up to one and a quarter inches long. The color varies, but many have dark bodies. The wings are pale. The wings may be yellow, gray, or even clear.