I had a pair of ISA browns that I thought were old, but looking back they were about 2years old, and they died. They'd stopped laying for about 3months after a Tennis ball came over the fence and landed in their run. As far as I could tell they were eating and drinking fine, then I went out to see them and Dawn, the older girl, wasnt moving, and when I touched her she fell over. About a week later Dusk did the same thing, she was 'dead on her feet', fell over when I touched her, and when I came back to check on her (couple of hours) she was dead. I didnt know at the time to bring them inside, warm them, feed them etc.. so I huddled them up in their nests (warm n comfy I thought) and came back to find them dead. Any Ideas why this happened?? Really dont want it to happen again.