Tick repellent is a product that is used to prevent ticks from attaching to the skin. The most common active ingredient in tick repellents is DEET, which stands for N, N-diethyl-meta-toluamide. DEET is an odorless chemical compound that has been used as an insect repellent since the 1940s. It is effective against a wide range of insects, including ticks, and is available in various concentrations.