The National Pesticide Information Center explains that citronella repels mosquitoes by masking scents that mosquitoes are naturally attracted to, which in turn makes it difficult for mosquitoes to locate food. Citronella does not cause harm to mosquitoes or other insects. Citronella candles are specifically designed for outdoor use and should also not be lit in semi-enclosed areas, such as screened-in porches or garages.
Citronella masks carbon dioxide and lactic acid in humans, two scents that are attractive to mosquitoes. Citronella oil is all-natural and consists of distilled oils from several varieties of grass. Citronella is approved by the Food and Drug Administration and is a common ingredient in various foods and beverages. Aside from causing a mild allergic reaction in certain individuals, citronella oil is considered safe and non-toxic to humans and animals, as it is broken down and secreted through the urine if ingested.
Citronella products include candles, bands and animal collars. Unlike candles, citronella bands and collars are not affected by wind or rain, allowing for optimal protection. In addition to repelling mosquitoes, citronella oil also works well to treat fleas on cats and dogs. Citronella has antibacterial properties and is often used as a natural remedy for viruses and infections.