Prevent-a-mite is the best! buy some and spray every encloser, walls substrate etc. remove animal of course, and water dish spray down its encloser, wait a few minutes for it to settle and then return the animals minus the water dish. wait a day or two then return the water dish. after about a week repeat process and you mites will be gone, i like to spray outside the enclosers as well, ie, if you have a rack system spray down the shelves. Black night is awsome as well but only for spray outside the enclosers, I use to think it was safe to spray the animals since some people out there had me believing it was safe so I would put snakes in a pillow case and spray into the pillow case with the animals inside and ended up either killing them or giving them perminant brain damage. I will never do that again, but if you spray black knight in a corner of the room that the animals as in for just a few seconds it will not only kill every mite in the room, but you will find dead insects and arachnids all over your house. So to kill on a large scale spray black knight but make sure to spray in a corner opposite of the enclosers. Prevent-A-mite is awsome because it has a lasting effect, ie you can spray down news paper let it dry then place the news paper in the animals encloser for substrant and it will still kill all the mites on the animal. and when the eggs hatch they will immdediately die as well even though it was few days since you sprayed. I repeat the process a week later to make sure that the problem is solved and all the mites are long gone.
whenever you get a new animal you should keep it seperate from the rest of your animals, use sprayed down newspaper (prevent-a-mite) for the new animals encloser and after a day if their is no dead mites on the newspaper you know your new animals is clean and can be put in with the rest of your animals.