Small flying insects, commonly referred to as “gnats,” often create a nuisance by hovering around people indoors and outdoors. Understanding why they are attracted to individuals can help in managing their presence.
Identifying the Common Culprits
The term “gnat” is a general descriptor for various small, non-biting flies. Common types found near humans include fruit flies, fungus gnats, and drain flies. Each has distinct characteristics and preferred breeding grounds.
Fruit flies are yellowish-brown with red eyes, drawn to ripe or fermenting fruits and vegetables. About 1/8 inch long, they hover around fruit bowls or compost bins. They lay eggs on decaying organic materials, where larvae feed and develop within a week or two.
Fungus gnats are slender, dark-bodied flies resembling small mosquitoes, about 1/16 to 1/8 inch long. They thrive in moist soil, especially in overwatered houseplants or high humidity. Their larvae feed on fungi and decaying plant matter in soil, while adults fly erratically around potted plants or windows.
Drain flies, or moth flies, are fuzzy, dark-winged insects with a distinctive “V” shape when at rest, about 1/16 to 1/4 inch long. They are found in drains, sewers, and other areas with stagnant water and accumulated organic sludge, which serves as their breeding site and food source.
Why You Attract Them
Small flies are drawn to humans by biological cues. A primary attractant is the carbon dioxide (CO2) exhaled during breathing. This gas signals the presence of a potential host or food source, acting as a long-range beacon guiding them towards individuals.
Body heat emitted by humans is an attractant, as many insects are thermoreceptive and use temperature gradients to locate targets. Human sweat contains moisture, salts, and organic compounds like lactic acid and ammonia, appealing to flies seeking hydration or nutrients. Microbial activity on human skin also produces volatile organic compounds that attract certain insect species.
Skin oils and residues from personal care products, such as lotions, hairsprays, or perfumes, can mimic natural scents that attract flies, especially if they contain sweet or fruity fragrances reminiscent of fermenting plant matter. Fruity notes in some shampoos or body washes are enticing to fruit flies. Food or drink residues on skin or clothing, like a spilled sugary drink or crumbs, provide a direct food source, drawing opportunistic feeders closer.
Minimizing Their Presence
To reduce the presence of small flies, several personal and environmental strategies can be employed. Maintaining good personal hygiene is a primary step, as regular showering helps remove sweat, skin oils, and lingering food residues that might attract them. Wearing clean clothes prevents the accumulation of these natural attractants on fabric fibers.
Being mindful of food and drink consumption is another important measure. Promptly cleaning up spills on skin or clothing, and avoiding leaving open containers of sugary beverages or uncovered food, eliminates readily available food sources. Indoors, storing ripe fruits in sealed containers or refrigerating them, and promptly disposing of overripe produce, prevents fruit fly attraction.
Environmental adjustments also deter these flies. Using a fan creates air currents that make it difficult for them to fly steadily, blowing them away. If strong fragrances in personal care products attract them, opting for unscented alternatives is beneficial. Addressing the source of an infestation is a long-term strategy. This includes allowing overwatered houseplant soil to dry out between waterings to manage fungus gnats, and thoroughly cleaning drains to eliminate organic sludge that serves as drain fly breeding sites.