Found one of my 14 month old hens dead the other morning. She was the "bottom of the pecking order" having obvious feathers missing on her back and chest. Always keep the coop clean with fresh water and crumbles. Heat could not be a factor because it hasn't been that hot yet plus the coop has plently of ventilation and a fan, and the hens have access to outside shade as well as sun. Could her death have been caused by one or more of the other 9 hens? ALSO: one or more of the hens are egg-killers. Hardly does a few days pass where one or more eggs are eaten for their yolks. Thoughts?