Curtains? Walls? Ceiling tiles? Cats mark in so many wonderful places. No matter how clean we kept the last place where we kept cats, there was always a hint. This is why they went to live at the farm when we moved here.

Tomorrow my wife is going to a house where there are usually 10-17 cats walking all over everything, and I don't think they use litterboxes. At least by the smell I think they don't.

*gack*