its protein, that's what they need, how they know its protein is beyond me. knew a guy once who kept shed antlers on the porch of his cabin, they started coming up missing, he would find the odd one in the yard or in the woods closeby, chewed to pieces, when it snowed, only tracks coming up the steps were deer tracks, sheds were gone again
RR
edited to add: just remembered this
https://www.google.com/search?site=&....0.j3srN2zAy7s