Gnat bites can be prevented by wearing long-sleeved clothing and using a repellent. Repellents include commercial DEET-based sprays and essential oils, such as peppermint or pine oils.
To prevent gnat bites, lightweight clothing that covers the arms and legs should be worn when spending time outdoors, and the hems of clothing, exposed socks and shoes should be sprayed with an insect repellent that contains DEET. Repellent should be reapplied every eight hours, or as directed, and spraying the skin directly should be avoided to minimize exposure to the chemical ingredients in the spray.
Products that contain geraniol are an alternative to DEET-based sprays. Geraniol repels insects for up to two hours. According to Today, geraniol is safer than DEET and works just as effectively. Other skin products should be avoided for 30 minutes before and after applying the repellent to ensure the geraniol maintains its effectiveness.
Essential oil can be used to prevent gnat bites by mixing a solution of 1 to 2 percent essential oil with water, then spraying clothing and skin. Any combination of essential oils, including a single oil, can be used to deter biting pests. Essential oils that help prevent insect bites include eucalyptus, peppermint, cedar and geranium. The mixture should be shook well before each use, and using undiluted essential oils on skin should be avoided. The mixture can be reapplied every four hours.