Gnats are tiny insects that often target the human face, turning outdoor activity into a frustrating experience. These small flies, which can include biting midges, black flies, or non-biting fungus gnats, are not drawn to humans randomly. Understanding the biological factors that attract them to your head and face is the first step toward effective prevention.
Why Gnats Swarm the Face
Gnats are drawn to the face by a combination of sensory cues that signal moisture, warmth, and sustenance. The most significant attractant is the carbon dioxide (CO2) exhaled with every breath, which insects like gnats use to locate potential hosts from a distance. The concentration of CO2 is naturally highest near the mouth and nose.
Once a gnat is closer, other factors keep it hovering near the eyes, ears, and mouth. The moisture found in sweat, tears, and the humidity of the breath provides the hydration and salt that gnats seek. Heat emanating from the head also mimics the warm, damp environments where gnats thrive, making the face a prime target for swarming behavior. Furthermore, natural skin oils and scents from cosmetic products like lotions and hairspray can attract them, providing a sensory anchor for the insects.
Applying Topical Repellents
The most direct method to keep gnats away from the face involves the use of topical insect repellents. Synthetic options like Picaridin and DEET offer the most reliable and long-lasting protection. Picaridin, a synthetic compound resembling a natural pepper plant extract, is often preferred for facial application because it is nearly odorless and less likely to feel greasy on the skin.
Picaridin is highly effective against gnats and biting flies, with concentrations around 20% providing maximum protection for up to eight hours. DEET concentrations of 25% to 30% offer excellent duration against a wide range of insects. However, DEET has a stronger odor and can feel oilier, requiring more caution when applied near sensitive facial skin and eyes.
For application, avoid spraying directly onto the face, which risks getting the product into the eyes or mouth. Instead, spray the repellent onto your hands first, then carefully dab it onto the forehead, cheeks, neck, and behind the ears. Oil of lemon eucalyptus (OLE) is a plant-based alternative that contains the active compound p-menthane-3,8-diol (PMD). OLE products approved by the Environmental Protection Agency can be as effective as lower concentrations of synthetic repellents, but typically require reapplication after four to six hours.
Physical Barriers and Environmental Adjustments
For high-infestation areas, a fine-mesh head net provides a physical barrier that gnats cannot penetrate. These nets are designed with an ultra-fine mesh, small enough to block even tiny biting midges and “no-see-ums.” Wearing the head net over a wide-brimmed hat is recommended, as this keeps the mesh material away from the skin, preventing gnats from biting through the fabric.
Making simple adjustments to your routine can reduce gnat attraction. Gnats are drawn to sweet or floral scents, so switch to unscented personal care products, such as lotions, sunscreens, and hairspray. Since gnats seek out moisture, frequently wiping sweat from the face and neck during outdoor activity helps eliminate this attractant. Gnats are most active during the low-light hours of dusk and dawn, so avoiding outdoor exposure during these peak times limits encounters.