During the twilight hours of summer, when mosquitoes typically come out to feed, mosquito coils can make being outside a more pleasant experience. However, commercially manufactured mosquito coils, while effective, may contain harmful ingredients. According to a University of California, Riverside, study, these mosquito coils "often contain up to one-percent BCME, which stands for bis (cloromethyl) ether, which is a dangerous, lung-cancer causing chemical." Making your own repellent at home using citronella oil, which contains a citrus-like scent that prevents mosquitoes and other pests from locating a host on which to feed, will keep these chemicals, and mosquitoes, from ruining your good time outdoors. Although they won't be in coil form, these homemade repellents work on the same principle as commercial mosquito coils.
Apply citronella oil to the incense sticks. Since citronella oil is normally available in 1-ounce bottles, apply the oil by hand, rubbing it onto the incense sticks. A cotton swab works well if you don't want to get the oil on your fingers.
Let the incense sticks rest for 10 minutes to allow the incense to absorb the citronella oil.
Place the incense sticks into incense holders and distribute them evenly around the patio or outdoor area where mosquitoes are a problem.
Light the incense sticks, blowing out the flame once lit. When the incense sticks burn out, replace them with fresh citronella-soaked incense.