Deet

N,N-Diethyl-meta-toluamide, also called diethyltoluamide or DEET (, from DET, the initials of di- + ethyl + toluamide), is the oldest active ingredient, and one of the most effective and common, in commercial insect repellents. It is a colorless to slightly yellow oil intended to be applied to the skin or to clothing and provides protection against mosquitoes, biting flies, ticks, fleas, chiggers, and leeches.