I hobbled out to my coop to check on my girls last night (hobbling because I just had knee replacement) when I noticed what appeared to be a rotten potato on the ground. I asked DW if she had given the girls a potato for some reason and she said NO. She went in the coop and found an egg with no shell, membrane intact and looking rather nasty. It looked very bloody. We opened it and the yolk looked fairly normal but the egg white looked more like puss. It also had a nickel size black spot that almost looked like a partially digested bug. Chickens all look and act fine. But was missing an egg this morning. Should I be worried? Does anyone know what this could have been?