Revolution is a medication that is applied directly to your furry friend's skin to protect them from biting critters. When applied every 30 days, Revolution protects against heartworms and fleas. It may also be effective in preventing and treating ear mites, roundworms, and hookworms.Revolution kills adult fleas and prevents flea eggs from hatching for one month. It is also indicated for the prevention and control of flea infestations, prevention of heartworm disease caused by Dirofilaria immitis, and the treatment and control of ear mite infestations. Revolution is also indicated for the treatment and control of roundworm and intestinal hookworm infections in cats.