Midges are a diverse group of small, flying insects, and the answer to whether they bite humans is a definitive yes, although not all species are blood-feeders. The term “midge” is a common name applied to many tiny flies, which can lead to confusion about their behavior. However, the subset known for their irritating bites can significantly affect outdoor experiences. Understanding which midges bite, the nature of their attack, and how to manage the resulting irritation is the first step in avoiding them.
Which Midges Bite Humans
The insects primarily responsible for biting humans are members of the genus Culicoides, commonly known as biting midges or “no-see-ums” due to their diminutive size, often less than three millimeters long. These tiny flies belong to the family Ceratopogonidae, distinguishing them from harmless relatives, like the non-biting midges (Chironomidae). The act of biting is exclusive to the female midge, a necessary biological function for reproduction, as they must consume a blood meal to develop their eggs successfully.
Male midges feed on plant nectar and are not a nuisance to humans, but females actively search for a host. The female is attracted to the carbon dioxide, body heat, and certain chemicals emitted from mammals. This need for a blood meal drives their biting behavior, especially near their breeding sites in damp or marshy environments. Their presence can be intense in low-wind conditions, as they struggle to fly when air currents are strong.
Understanding the Bite and Skin Reaction
When a female biting midge lands on the skin, it uses specialized mouthparts that function like miniature cutting tools, rather than a needle-like proboscis. The midge pierces and tears the skin’s surface, creating a small wound to draw blood, a feeding method often described as “cut and sponge.” To ensure continuous flow, the midge injects saliva containing an anticoagulant into the site, which triggers the body’s immune response.
The typical reaction to a midge bite is the development of small, intensely itchy red welts or bumps that may appear in clusters. These reactions are caused by the body releasing histamine in response to the midge’s saliva. While some people feel an immediate sharp prick, the most irritating symptoms often develop hours after the bite, sometimes worsening the following day. Bites tend to target exposed skin, such as the neck, arms, ankles, and legs.
Immediate Relief for Midge Bites
The first action after a bite should be to gently clean the affected skin area using mild soap and water. Applying a cold compress or an ice pack wrapped in a cloth to the bite site for 10 to 15 minutes can help reduce swelling and numb the intense itching sensation. This cooling technique helps to slow the localized inflammatory response.
Over-the-counter topical treatments are effective for managing persistent discomfort. Creams containing hydrocortisone or lotions like calamine can be applied directly to the welts to soothe the skin and reduce inflammation. Taking an oral antihistamine can also help control the body’s systemic reaction, particularly if multiple bites are present or the itching is severe. It is important to resist scratching the irritated areas, as breaking the skin can lead to secondary bacterial infection.
Avoiding Midge Encounters
Successful midge prevention involves personal protection and strategic avoidance of their peak activity times. Biting midges are most active during calm, humid conditions, particularly around dawn and dusk; limiting outdoor activity during these periods reduces exposure. They congregate in environments with high moisture, such as near stagnant water, marshes, and dense vegetation, which are their preferred breeding sites.
Applying an effective insect repellent to all exposed skin is the most direct line of defense. Repellents containing active ingredients like DEET (diethyltoluamide) or Picaridin are effective against biting midges. Picaridin is often preferred as it is less likely to damage plastics and synthetic fabrics than DEET. Wearing light-colored, long-sleeved shirts and long trousers also provides a physical barrier.