You will need to treat for the mites. Provent a Mite is your best bet. http://www.pro-products.com/miteandtemp.html

This product is used to treat the cages, and not the snake directly. It also is the only one that will kill any eggs and prevent a re infestation. I would go ahead and treat the other two snake cages, but you should have to worry about any warm blooded critters.