Sometimes Revolution requires several treatments to totally get rid of the earmites. It's certainly better than giving ear drops.

Jack had horrible earmites when he showed up and we had to do the drops twice a day for a whole MONTH! The poor guy hated having his head touched for a year after that! When the 3 kittens got earmites it took two doses of Revolution and they were gone. Too bad they didn't know about Revolution and ear mites when I got Jack.