When people speak of midges, they are referring to extremely small, flying insects that appear in large numbers, particularly near water. These creatures are common throughout the world, and the term “midge” refers to a diverse group of insects. This diversity means their dimensions vary, but their individual scale is consistently minuscule.
Defining the Midge
The term midge is not a precise scientific classification but rather a general name applied to several distinct families of small flies, all part of the order Diptera, or true flies. To understand their size, it is helpful to distinguish between the most common types.
Non-biting midges (Chironomidae) are most frequently seen in large, harmless swarms. Conversely, biting midges (Ceratopogonidae), often called “no-see-ums,” are responsible for painful, irritating bites. Other related groups, like black flies (Simuliidae), are also sometimes grouped under the general “midge” designation.
Actual Physical Dimensions
The most accurate measurement for a midge is its body length. The smallest species, the biting midges, typically range from one to three millimeters long. This tiny size is why they are often referred to as “no-see-ums,” being barely larger than a pinhead.
The non-biting midges show a greater size variation. Many common species fall into a range of two to ten millimeters in length. Some larger non-biting species can reach up to 13 millimeters, roughly half an inch, making them the largest of the group. Even the largest midges are slender and delicate.
Swarming Behavior and Perception of Size
The perception that midges are larger is due to their collective behavior, specifically their instinct to form dense mating swarms. These swarms, often comprised almost entirely of males, serve as a focal point to attract females. The males accelerate toward the center of the group to keep the swarm intact, creating a highly concentrated cloud of insects.
This dense gathering can form an elliptical shape and be several feet high, transforming thousands of tiny individuals into a visually substantial mass. The high number of insects flying close together creates a visual effect that can resemble a column of smoke or a dark cloud. This collective display makes the insects appear more substantial than their individual bodies would suggest.