Under the bed's another prime spot. I was once mystified by a series of vanishing gloves, and thought they might have been stolen and chewed up by the dog, until I caught my cat in the act of dragging one upstairs. (Particularly startling as she is a very tiny cat, and the glove she was dragging was a very large man's fur-lined leather glove almost as big as her body) -- it turned out she had a Seekrit Glove Stash dead center under the bed.