when did you put the stuff in? probably just wondering what happened to his house. takes a week or so for them to check things out. what kind of cork bark anyway? stuff he can go behind? and is there background behind the cork bark too? won't go behind it unless it is dark behind there. and if you are using a cork round with a big gap they won't use that either. they need a tight fitting hiding place. truthfully I would get rid of the jar and see what happens then. I can't imagine the setup needs that.