Many plants have insecticidal properties so they are also called natural insecticides. The orange (Citrus sinensus), is a valuable fruit not only for its edibility, but for the high quantities of the substance d- limonene, found in its peel and zest. D- Limonene is a pesticide and is found in many commercial insect repellents.Oil derived from orange peel has a 90 to 95 percent content of d-limonene, which is lethal to fleas, fire ants and flies. Limonene affects insects on contact, effectively suffocating them by damaging their respiratory systems. Many insects such as roaches, ants and silverfish do not care for the scent of orange oil and will avoid it. Placing bits of orange peel or zest around the garden repels flies and mosquitoes. Rubbing orange peel on the skin is a home remedy for preventing mosquito bites. It will smell wonderful and repel the mosquitoes with no side effects on human health. When we apply the orange extract on skin, the mosquito could not bite because the active ingredients does not allow it to smell the attractant (lactic acids) and could not therefore identify the human as its source of meal. Sometimes, theskin itching and the sneezing reactions experienced by the human volunteers can be regarded as mere individual allergy especially as the reactions were mild and short-lived.