I went to let the chickens out this morning and noticed our year and half year old black sex link just laying in the coop. She wasn't moving and when I reached in she was hard. I don't know what happened to her and I was hoping maybe I could get some ideas from you guys. She had been our first layer when we got our chickens last year and she laid great all summer but then stopped in winter and since then has laid very inconsistently, and most of her eggs have had a very soft shell even though we provide oyster shell. She had one pupil that was shaped like a tear drop and seemed to have a bit of a balance problem. We spoiled our chickens and I had to go out every night and put her on the roost because she would try to sleep in the egg box. When I put her up there she would seem fairly wobbly but would stay on the roost through the night. When I found her this morning I checked over the body but it was pretty stiff. I noticed that the vent was slightly prolapsed. I did not notice this yesterday, but it is possible I just didn't see it. I also don't know if this may have happened after the death. Is it possible that a prolapsed vent may have been the cause of the death or a symptom? The body in general was so stiff that I couldn't really tell if there was was an egg bound up in there. She had laid a very soft egg two days ago. Any thoughts on what might have happened or what I should check the body for would be appreciated. My wife is going to be extremely upset and I want to make sure that it isn't something that may be contagious so that we don't lose our other chickens. Thanks.