I had a year-old Polish Chicken who was killed yesterday through a dog run that is covered in chain link that is also covered in chicken wire and a cement floor. Found her on the ground by the side of her roost against the side of the coop. Head had multiple injuries and a few bloody feathers beside her. Nothing got inside the coop. She was killed from the outside. There had been a raven hanging about the chickens and the chickens huddled in a corner and made a big racket. We heard nothing so I am thinking whatever attacked her through the kennel at night. We have skunks, racoons, opossums, owls, hawks and coyotes. I am thinking none of those could reach through the small opening in the chicken wire to get her. Any ideas and how can I better predator proof my coop?