I went to my chicken coop this morning to feed them. I had 5 - 3 month old's. Three were completely missing and one outside the pen with its stomach ripped open. I had wire around the base of the coop and pheasant netting over the top. Something came in and put a six inch round hole through the top of the netting got in took three chickens out and left one outside the door. The only thing that I can see is it had to go back out through the hole which is about 4 feet above the ground. What could it be and why didn't get caught in the netting trying to get out?