I am posting this for a friend of mine. She has a broody (Black Australorp) that is setting on 9 eggs. Today is day 18. She went out to check on her today and noticed her picking on something. So she moved her broody and found that there was a chick - fully developed in the nest. The shell looked like is was smashed rather than it would if a chick had hatched. The mama hen was eating the yolk sack and the egg shell. She chick was warm, but dead. She tried to revive it, but it was dead. It was obvious that this just happened a few minutes before. After my friend removed the egg shell, yolk, and chick the mama hen sat right back down and resumed setting. What could have happened? Any suggestions?