Owls consume the entire body of their prey, including bones, teeth, fur, feathers and/or scales. Once the good parts have been digested, the owl's stomach compacts this all into a neat, little packet. Then the pellet is regurgitated.

Ornithologists collect these pellets, and use them to learn about what the owls have been eating. You can even buy owl pellets online, to take apart yourself. Care should be taken if you collect your own owl pellets, as they can contain viruses and bacteria from rodents that the owls eat.