These are pellets collected by my daughter and I on our farm. We've loved dissecting them for years, but honestly are a bit buried by all our beautiful birds of prey! I have no idea who vomits up which ones, but you're getting a mix of barn owl, screech owl, and great horned owl. Every one is unique, but with ten in a bag there's always at least one skull (I toss in extras as I can for fun too) and lots of other parts.These are NOT pasteurized, but if you choose to, that is easy to do- look online for directions for temp and time. Poke apart nicely with a stick- no fancy tools required for kids to have a great time. Don't pay extra for fancy kits- all directions, bone charts, etc are online, and you already own the gear you need! Enjoy !!!