Zodiac Spot On Plus - Flea and Tick Control for Cats and Kittens has Etofenprox and Methoprene as the active ingredients. The combination of these two ingredients helps kill not only fleas but lice, ticks, and mosquitoes too. Etofenprox is a safe ingredient, unlike other pyrethroids that cause harm to felines. Contact your veterinarian to know more about the efficacy and safety of the Zodiac Spot On.