In case you didn't know, owls regularly produce owl pellets: blobs of regurgitated bones, fur, and other bits that doesn't make it through their digestive tracts. Once dried up, these little nuggets of wonder are fascinating to dissect, as they provide a mostly-intact accounting about what the owl just ate.
You can buy ready-to-dissect owl pellets. Another option: make your own! No vomiting required!
This project comes from Martha Stewart, which makes it all the more delightful because it's funny to think about Martha Stewart crafting animal barf.
I first learned about owl pellets because pellet dissection was the highlight of a recent hands-on science program at my daughter's school. She came home with a tiny bag full of tiny bones, and a HUGE smile on her face. If you think your kid might be interested, the book/pellet kit Owl Puke would make a great gift.