We have three chickens who put themselves to bed each night in thier chicken house. Tonight, when I went to lock up the coop and check the chickens were OK I found that one was missing. After searching the garden I found one egg with a really thin flexible shell and then I found the chicken, she was standing next to another egg, even more unformed this time, pretty much just yoke. She sounded like she was crying, her breaths were "moany", its hard to explain. I put picked her up and comforted her for a bit before putting her to bed with the other two hens, she seemed better once she'd seen the others and walked as normal into the hen house. I don't know if its anything to do with it but there was a big slug next to the second egg when I found her and she seemed to be gagging a little. Perhaps she'd eaten the slug earlier and it had made her sick!? She was fine earlier on today so its wierd, has anyone experienced anything similar to this before?