Could these be from a shed? Just want to make sure my boy is good...
If it's shed it should come off. You could try touching it very gently with a damp paper towel or q tip to see if that takes it off. Please post again to let us know if that happens.
If it's too upsetting for him you can wait a bit and see if it comes off. If it doesn't or gets bigger then it could be something else and you should post in this thread again.