Flies often persistently buzz around individuals, but this behavior is not random. They are drawn to humans for various biological reasons, seeking resources for their survival. Understanding these attractants can explain why they appear to single out certain people.
Why Flies Are Drawn to You
Flies are equipped with highly sensitive detection systems to locate resources. One primary attractant is the carbon dioxide (CO2) humans exhale, which flies can detect even in small concentrations. This gas acts as a signal, guiding them toward a potential host. Flies also sense the warmth emanating from the human body, as they are cold-blooded insects.
The skin’s surface provides a rich source of nutrients for many fly species. Sweat contains salts, carbohydrates, and proteins that flies consume using their sponging mouthparts. Body odor, which results from bacteria on the skin breaking down sweat, also acts as an alluring scent. Natural skin oils and dead skin cells provide sustenance.
Flies are also attracted to open wounds or scratches, as these provide a moist, warm environment rich in nutrients like blood and tissue fluids. These sites are ideal for flies to feed and lay eggs. Spilled food, sugary drinks, or crumbs on clothing can also draw flies.
Common Types of Flies That Bother Humans
Several fly species commonly bother humans, each with distinct attractants. House flies (Musca domestica) are drawn to decaying organic matter, garbage, and food. They often land on humans due to proximity to these sources and can taste the skin’s surface for nutrients.
Fruit flies (Drosophila melanogaster) are typically attracted to ripening or fermenting fruits and vegetables. They may hover around people carrying or consuming these items, or those using sweet or fruity scents. These flies can quickly reproduce, leading to rapid increases in their population around food sources.
Gnats, a broad term for various small flying insects like fungus gnats or biting midges, are common nuisances. Many gnats are attracted to moisture, humidity, and the CO2 and heat produced by humans. Some species, particularly biting midges, seek blood meals for reproduction, causing itchy bites.
Biting flies, such as stable flies, horse flies, and deer flies, actively seek blood meals for egg production. These flies are attracted to CO2, body warmth, movement, and certain body odors. Their bites can be painful, as they use specialized mouthparts to cut the skin and lap up blood.
Keeping Flies Away From You
Managing personal hygiene can significantly reduce fly attraction. Regular bathing helps remove sweat, salts, and skin oils that flies find appealing. Changing sweaty clothes frequently also eliminates attractants.
Proper food management is an effective strategy. Promptly cleaning up food spills, covering food, and disposing of trash in sealed bins reduces food sources for flies. Ensuring pet waste is properly managed also helps control odors that attract flies.
Environmental controls can limit fly entry into personal spaces. Using screens on windows and doors prevents flies from entering homes. Good ventilation can also reduce indoor humidity, which attracts some gnat species.
Insect repellents offer personal protection. Products containing DEET or picaridin are effective against many fly species. Natural alternatives like citronella, lemon eucalyptus oil, peppermint, rosemary, and lavender essential oils can deter flies. Wearing protective clothing, such as long sleeves and pants, creates a physical barrier against biting flies.