There are good mites and there are bad mites the good ones live in soil mostly but sometimes get on the lizards to eat dead skin. The lizards usually appreciate this assitance with their molting.The bad ones suck blood and untreated can eventully be fatal. The blood sucking kind with turn red when engorged with blood and live in folds around the eyes and mouth, nostrils. If you have those then you want to empty the cage of any subtrate, cook or destroy any driftwood and hang a mite strip until they are gone.