Gnats are a collective term for various small, winged insects in the fly order Diptera, including mosquitoes and midges. These tiny flies are common in many environments, often swarming around moisture or light sources. A frequent question is whether these insects can bite humans, especially after experiencing itchy welts outdoors.
The Truth About Gnat Bites
Not all gnats bite, but certain species do. The term “gnat” is broad, encompassing various tiny flies, and only specific types are known for biting. For instance, fungus gnats, commonly found around houseplants, typically do not bite humans. However, female gnats from species like biting midges (“no-see-ums”), black flies, and sand flies require a blood meal to produce eggs.
Biting gnats use specialized mouthparts to feed. Unlike mosquitoes, which pierce the skin, gnats often use scissor-like jaws to cut the skin. This creates a small wound from which they draw blood, a process that can take a few minutes if undisturbed. During feeding, they inject saliva containing anticoagulants, which prevents blood clotting and triggers an allergic reaction, causing itching and irritation.
Recognizing and Relieving Gnat Bites
Gnat bites typically manifest as small, red, itchy welts, often resembling mosquito bites but sometimes appearing smaller or more numerous. These bumps can be painful and may swell, with reaction severity varying among individuals. A tiny drop of blood might be visible at the bite site, or bumps could develop into fluid-filled blisters. Bites commonly occur on exposed skin areas like the face, ears, neck, arms, and legs.
For immediate relief from gnat bites, clean the affected area with soap and water. Applying a cold compress or ice pack can reduce swelling and alleviate itching and pain. Over-the-counter anti-itch creams containing hydrocortisone or calamine lotion can also soothe irritated skin. Taking oral antihistamines may further reduce the body’s allergic response, lessening itchiness and irritation.
Keeping Gnats Away
Preventing gnat bites involves personal protection and environmental management. When outdoors, wear protective clothing like long-sleeved shirts, long pants, and closed shoes to shield exposed skin, as gnats cannot bite through fabric. Applying insect repellents containing active ingredients like DEET or picaridin to exposed skin is effective. Oil of lemon eucalyptus offers a plant-based alternative.
To reduce gnat populations around homes, manage moisture, as many gnats breed in damp environments. Eliminate standing water sources like clogged gutters, leaky pipes, and overwatered plants to minimize breeding grounds. Ensure window screens are intact, or install fine-mesh screens, to prevent tiny gnats like no-see-ums from entering indoor spaces. Using fans outdoors can also deter these weak fliers from congregating.