I recently (a few months ago) switched substrates from aspen to newspaper. My ball has been spending the majority of its time curled up underneath the paper (as opposed to the hides). Today I noticed some black "smudges" on his belly. I assumed it was on the outside and tried to wipe it off unsuccessfully. It seems to be between the scales. Is this scale rot ( I realized that he may have urinated on the floor of the cage under the paper, and sat in it), and if so what should I do about it?
Also is one substrate (aspen/newspaper) superior to the other? And what can be done about preventing hiding under the paper?
Thanks


