While many small flying insects are broadly referred to as “gnats,” not all of them bite humans. The term “gnat” describes various tiny, winged flies; some are harmless, while others can deliver irritating bites.
Not All Gnats Bite
Many species, such as fungus gnats often found around houseplants and drain flies that inhabit sink drains, do not bite humans. These non-biting gnats primarily feed on decaying organic matter or fungi.
However, certain types of gnats are equipped to bite, and these are often encountered outdoors. Examples of biting gnats include no-see-ums (also known as biting midges or punkies), black flies (or buffalo gnats), and some species of sand flies. Female gnats of these biting species require a blood meal to produce and develop their eggs, which is why they seek out mammals, including humans, for feeding. Unlike mosquitoes, which use a needle-like proboscis to pierce the skin, biting gnats often use scissor-like mouthparts to cut the skin, leading to a small wound from which they feed. This cutting action can result in a more immediate and noticeable sensation compared to a mosquito bite.
What Gnat Bites Look Like
Gnat bites typically manifest as small, red, itchy bumps on the skin. The appearance can often resemble mosquito bites, though gnat bites may sometimes be smaller or appear in clusters. Reactions to gnat bites are primarily caused by the body’s response to the gnat’s saliva, which contains anticoagulants to facilitate blood flow.
The immediate sensation of a gnat bite can range from an unnoticed nibble to a sharp sting, followed by varying degrees of itchiness. Swelling and redness around the bite are common, and some individuals may experience a more pronounced reaction, including the formation of welts or, in less common instances, fluid-filled blisters. The intensity and duration of symptoms can differ significantly from person to person, with itching potentially lasting for several days or even weeks.
How to Avoid and Treat Gnat Bites
Using insect repellents containing active ingredients such as DEET, picaridin, or oil of lemon eucalyptus can be effective in deterring biting gnats. Wearing protective clothing, like long-sleeved shirts and pants, especially when outdoors, can also create a physical barrier against bites, as gnats cannot bite through fabric. Since many biting gnats are most active during dawn and dusk, avoiding outdoor activities during these times can reduce the risk of being bitten. Ensuring windows and doors have intact screens can help prevent gnats from entering indoor spaces.
Begin by gently washing the affected area with soap and water to clean the skin. Applying a cold compress or an ice pack to the bite for 10 to 20 minutes can help reduce pain, swelling, and itching. Over-the-counter topical treatments such as calamine lotion or hydrocortisone cream can be applied to soothe irritation and reduce itching. Oral antihistamines, available without a prescription, may also be taken to relieve widespread itching and allergic reactions. It is important to avoid scratching the bites, as this can break the skin, potentially leading to secondary bacterial infections.