Owl pellets!  The boy just asked me, "mom.  Can we kill a bird and cut it open and see what's in it?". I'm going to assume it was something he saw on Wild Kratts.  Either way he has a chemistry set, microscope, box of motors, wires, and battery packs.  I was thinking, you just had to have "pouring science".  Can't that last a little while before you ask for something new?  I was going to wait until hunting season.  He's seen the deers skinned and hanging upside down, but he hasn't seen their guts.  I was going to ask a neighbor who hunts to help him dissect a hog or a deer instead of buying a frog.  But it sounds like owl pellets is maybe a starter to dissecting and identifying?
I'm typing this thinking it makes my kid sound a little strange.  Maybe it's just his mom that should say "ew" when he asks to kill a bird and see it's insides instead of thinking, really?!  Another Science kit?!  We just bought a Science kit not long ago!?  
Youth lives by personality, age lives by calculation. -- Aristotle on a calendar