Hey Gina!  I don't know either.  I usually clean Zeus' up while he is looking at me.  He looks at me as if he knows it was a no no and he looks a little embarrased.  I don't say anything to him, unless I catch him in the act.  I would like to know too, if this is the right approach.     
				__________________    Farrah, Zeus, Enja & Riley         |