My cat, Melodie (Mel), has an obsession with all types of bags and boxes. She gets very excited when I bring home groceries and there is a new paper grocery bag she can sit in.
There was an empty Michael's bag in my office. Well, Mel decided to poke her way in and sleep in it. I have no clue why the bag is comfier than just sleeping on the carpet, but that's a cat for ya!