Yesterday we found many of our chickens and most of our chicks scattered around the yard, dead.There were feathers in clumps in a few places. Many of them had been killed without many cuts, it looked like their necks were broken. In one case the chicken had the whole side pulled off with insides showing. One chicken was attacked and survived, but with cuts on her back, head, under the wings, and has been plucked near the cuts. Does anyone have any idea what attacked them?