So my five chickens, 2 RIRs and 3 buff orpingtons, were let out today to roam my back yard like they are every morning. They went out at about 7:00 am and at around 1:30 pm I came home and put them up (because it is hot and they need to shade up, and to let the dog out to do his business). When I came back to let them out for their evening roaming at around 6:30 pm, I found one of my rhode island reds dead in the nesting box. She was turned on her side, and her legs and body were already kind of stiff. Her neck was limp and she was still somewhat warm as if she had died somewhat recently. Her eyes were closed, cloudy and seeping a little. Her comb was dull and discolored. I checked her body for injuries and found none, I also checked her for mites and did not see anything moving around on her. I looked at her vent, and it was slightly red and sticking out a tiny bit more than usual, but if she was egg bound I don't think she would have died from that in less than 5 hours. It did not feel like an egg was stuck above her vent, but I am not sure. I did not see any blood around her vent. I picked her up to take her to the coop for the afternoon like I do every day. I grab them by the top of their wings and hold them primarily by their breast bone with my hands over their wings (to keep them from flapping). My hands are never really on their abdomen and I am gentle with them, so I don't think I broke an egg inside of her. Anyway, when I caught them one at a time to put them in the coop this afternoon, everyone seemed fine and healthy. They all ate some food and drank some when they got back in the coop. I went back to work, and when I returned to let everyone out, she was dead. Any ideas what could have happened? I've searched the forum some but wasn't sure everyone had provided enough detail. I tried to provide as much detail as possible (time frames, condition of carcass, etc). Let me know if you need any other info and I'll let you know. In case it was parasites (which I didn't see) I dusted the whole coop with DE. I'm just shocked because I thought we were taking really good care of these girls, they had been laying 4-5 eggs a day, were eating plenty and had seemed healthy right up until I found her dead today. Any advise or ideas would be greatly appreciated.