[cypher]

They do groom quite a lot & will often wash particularly their faces if they're nervous but he shouldn't be scratching too much, they most often show signs of mites around the eyes & or ears, unless he's become stressed for some reason I wouldn't think mites are likely unless you have something like hay or herbs in the cage that hasn't been in the freezer first.
I tend to err on the side of caution with mite treatment, with such tiny animals I think it better not to dose them with something like that without confirmation from a vet that mites is actually the problem.
If he does it in the ball that could possibly just be stress, as I said in another of your threads balls really aren't a good option for dwarf hams so maybe see how he goes if you stop using it.

You could try adding a few flax seeds to his diet too, great for keeping skin & coat in good condition & they love them!