Molly loves to hide

Is it normal for dogs to love enclosed spaces this much?  Molly loves crawling into tiny spots-- closets, under the couch, under the futon, under my desk, etc.  I have the opening under the futon blockaded with pillows, mostly because when she goes under there, I can't get her back out (the way in is small enough that she has to squeeze over or under it, so I can't pull her out without hurting her).

So she decided to climb on top of the pillow barricade to sleep.  Weirdo.