All of the bookcases in my house (five at last count) are fair game for Katie Kitten's need to make a mess and find hiding places or high perches. A couple of days ago she jumped on a shelf in my little office and shoved every single book onto the floor.
Here she is in the living room after using her paws to remove enough books so she could climb in behind them. She seems pretty satisfied with her work, doesn't she?

I took this next expression to mean I'd just better not even try to pull her out of there after she went to all that trouble.

So far, she hasn't used her teeth or claws on any of the books, so I let her have a bit of fun. It's better than having her walk across my keyboard when I'm writing.