The frontline spray works great! Get it if you can. I was told to take a q-tip and get a little of the spray on there, like a drop, and apply it to the back of all the rats/mice that I suspected of having mites. Within a few hours I saw the number of mites start to drop and by the next day I didn't see any mites and to this day I have not gotten any more. I don't have to use the frontline spray anymore but I keep it around just in case any new rats who come in have mites. It works great and the rats and mice were not affected in the least. Just apply it just like you would a cat or dog's flea meds, at the base of the neck. Depending on how many rats/mice you have to treat, a frontline bottle would last you a long time.