My not even 1 year old polish hen was found dead in the coop today. It's just my small flock of polish. I've been feeding cracked corn, layer feed and oyster shells. I checked her over and no sign of any puncture holes or any blood. She was fine last night. No signs of dropping or anything. So I'm very confused as to what happened. This is my first year with polish. Anything I need to know? Or can anyone make heads or tails to my situation?