I found one of my hens dead this morning with no signs of "fowl play." She was perfectly healthy yesterday - no sign of illness and she has no access to anything but what I feed her and the flock. She's completely intact, no blood on her and the others are fine. She was in a large enclosure with two other hens and a rooster. It's possible a predator got it and... scared her to death? Could she have run into the fence so hard she broke her neck? Could the rooster have crushed her? Or is there some Sudden Chicken Death Syndrome I'm not aware of? Any theories would be greatly appreciated!