A mosquito Coil has Been made by Govigyan Anusandhan Kendra in collaboration with VNTI, Nagpur. Its main ingredients are cow dung and cow urine. It acts as an insect repellent as well as purifies the air. The prienciple of Agnihotra was used while designing this coil. A project was undertaken (dept. of microbilogy, Shimoga college) to study the effect of Agniotra on air borne micro-organisms. The use of cow dung cake and cow's pure ghee releases Formaldehyde, Ethylene oxide, Propylene Oxide, B-propiolactone, acetylene. These gases are eco-friendly and they purfy the air, There was 100% reduction in fungal count and 94% reduction in bacterial count. they concluded that the Agnihotra ash can be used in seed treatment, soil treatment and human medicines also. Based on this concept the coil was manufactured and found that when burnt it releases bactericidal & fungicidal gases and thus helps purify the air. It keeps the mosquitoes away.