Midges are small, two-winged insects found globally, excluding permanent deserts and frigid zones. These flies are seasonally abundant, often noticeable due to their sheer numbers and presence near water bodies. All midges belong to the insect order Diptera, commonly referred to as true flies.
What Midges Look Like
Midges are small, delicate insects, typically measuring 1 to 12.7 millimeters, and often resemble mosquitoes. They possess a soft body, a single pair of narrow, clear wings, and six long, slender legs. Many species hold their front legs extended forward and upward when at rest, and male midges often have distinctively feathery antennae. Their coloration commonly ranges from gray, black, and brown to light green or red. While resembling mosquitoes, midges lack a long piercing proboscis; the term “midge” broadly refers to several insect families like Chironomidae, Ceratopogonidae, and Simuliidae, which share these visual characteristics.
Where Midges Live and How They Behave
Midges undergo complete metamorphosis, progressing through egg, larval, pupal, and adult stages. Larval and pupal development occurs predominantly in aquatic environments, such as ponds, lakes, streams, and damp soil, where they feed on organic matter. Larvae often burrow into the mud or construct small tubes; some species, like “bloodworms,” appear red due to hemoglobin content. Adult midges have a short lifespan, typically three to five days, with their primary purpose being reproduction.
Adult midges are well-known for forming dense swarms, particularly around dawn and dusk. These swarms are mostly composed of males, gathering to attract females for mating. The swarms often congregate over distinct markers like bushes, dark objects, or even people, providing a visual reference point. This collective behavior, sometimes appearing as “gnat-balls,” makes it easier for females to locate mates. While individuals constantly move within the swarm, the group maintains its overall shape.
Why Midges Matter to People
Midges interact with people in various ways, largely categorized by whether they bite. Non-biting midges, primarily from the Chironomidae family, do not feed on blood but can still be a significant nuisance. Their emergence in large swarms can disrupt outdoor activities and stain surfaces like vehicles and buildings. These swarms also attract other creatures, such as spiders, leading to increased cobweb presence around homes.
Conversely, biting midges, including species from the Ceratopogonidae (no-see-ums or sand flies) and Simuliidae (black flies) families, can inflict painful bites. Only female biting midges bite, as they require a blood meal to mature their eggs. Their bites typically result in small, intensely itchy red welts and localized swelling, which may appear hours after exposure and persist for several days. This discomfort arises from the body’s immune response to the midge’s saliva injected during feeding; some individuals may experience more pronounced allergic reactions. While generally not known to transmit diseases to humans, certain midge species can carry pathogens affecting animals.