Biting flies, including mosquitoes, gnats, and ticks, can make outdoor activities uncomfortable. Beyond itchy bites, some transmit pathogens causing illnesses like West Nile virus, Zika virus, Lyme disease, and Rocky Mountain spotted fever. Safe outdoor enjoyment requires effective strategies to repel these insects and prevent bites, combining topical repellents, physical barriers, and environmental management.
Effective Topical Repellents
Topical repellents are a direct way to deter biting flies. DEET (N,N-diethyl-meta-toluamide) is an effective repellent against mosquitoes, gnats, ticks, and blood-sucking flies. For adults, products with 15% to 40% DEET are recommended, providing one to three hours of protection, which may be shorter with swimming or heavy sweating. For children, products with no more than 8% to 10% DEET are suggested, as higher concentrations offer longer protection, not improved efficacy.
Picaridin, a synthetic compound, offers comparable effectiveness to DEET against certain mosquito species and ticks. Concentrations of 5% picaridin can provide three to four hours of protection, while 20% formulations may offer eight to twelve hours of repellency. Picaridin often has a more pleasant feel on the skin compared to some DEET formulations.
Natural alternatives include oil of lemon eucalyptus (OLE) or its synthesized version, para-menthane-3,8-diol (PMD). Products with 30% to 40% OLE can provide up to six hours of protection against mosquitoes. Only EPA-registered products containing OLE or PMD should be used, as “pure” essential oil of lemon eucalyptus is not tested for safety or efficacy as a repellent. Other essential oil-based repellents, like those with citronella or catnip oil, offer varying and often more limited protection against mosquitoes, and typically not against ticks. Choose a repellent based on needed protection duration and personal preference.
Physical Barriers and Environmental Control
Physical barriers offer an effective defense against biting flies. Wearing long-sleeved shirts, long pants, and closed-toe shoes minimizes exposed skin, reducing bites. Tucking pant legs into socks and shirts into pants creates additional barriers, preventing insects from crawling underneath clothing, especially in tick-prone areas.
Insect netting over strollers or baby carriers protects infants from bites without direct repellent application. Similarly, ensuring windows and doors have intact screens prevents flies from entering indoor spaces. These methods offer continuous protection without reapplication.
Environmental management reduces biting fly populations around your living spaces. Eliminating standing water in flowerpots, birdbaths, or clogged gutters removes mosquito breeding sites. Keeping outdoor areas clean and free of leaf litter and tall grasses deters ticks and other biting insects. Fans on patios or decks can also deter mosquitoes, as air currents hinder their flight.
Safe Application and Other Considerations
Proper application of topical repellents is as important as choosing the right product. Always read and follow product label instructions, applying only to exposed skin and outer clothing. Avoid applying repellents under clothing, or over cuts, wounds, or irritated skin. When using spray repellents, spray the product onto your hands first, then rub it onto your face, carefully avoiding eyes and mouth and using sparingly around the ears.
For children, supervising application is advised. Repellents should not be applied directly to their hands, as they frequently touch their face. Products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) should not be used on children younger than three years of age. After returning indoors, wash treated skin with soap and water and launder treated clothing to remove residue.
Repellents are most needed during peak insect activity times, such as dawn and dusk for many mosquito species, or when venturing into wooded or grassy areas where ticks are prevalent. If you have been in grassy or wooded areas, perform a thorough tick check on your body and clothing. Showering within two hours of coming indoors can also reduce the risk of Lyme disease transmission if a tick has attached.