they used to like boxes when they were kittens, not too much now, unless it is a big box, like one used for moving, one of the medium sizes makes a good cat "house". I used to cut holes in them, get 2 or 3 boxes and put them together even make a 2 story "house", haven't done that for a while, I might do that again this weekend. I tie or staple toys with a string to the "ceiling" so they have something to play with