Revolution is a monthly spot-on treatment to protect your cat from fleas, heartworm and other nasty parasites. Treats and controls ear mites. Revolution kills adult fleas as well as their eggs and larvae to break the lifecycle of fleas in the environment, protecting your cat for an entire month. Revolution also protects your cat from heartworm disease. Although heartworm is less common in cats than dogs, it is potentially fatal and there are no safe treatment options available, so prevention is essential. As well as providing month-long protection for your cat against heartworm and fleas, Revolution treats and controls ear mites, and kills roundworm and hookworm.