[cypher]

They do get a bit itchy sometimes & he may have been busy scent marking new things so doing a bit more grooming than usual, just wait a while & see if he settles down again.
With mites the itching scratching will go on pretty continuously & you can begin to see fur loss, they mostly get them around the eye & ear areas, unless you've put something new in the cage like hay which can have mites I doubt very much you have anything to worry about, other than that it's usually stress weakening the immune system that causes them to have a problem with mites but I don't think Bernie has any reason to be stressed so again nothing to worry about.