I have a Blue Cochin who was paired with another hen. We were away on vacation and had our neighbor taking care of our hens. When we returned late Friday night I went down to the coops and locked the girls in. In the morning I went down to let the girls out and found a hen dead in the pen. She must have died that night but I didn't see her because it was dark. I assumed they were both in the coop. There was no sign of trauma on the dead hen and no sign of any predators. Now the Cochin is very listless and drinks but will not eat. Her eyes are clear, her comb is bright and there are no signs of respitatory distress. Our neighbors said all was good all week with the usual egg production until the sudden death of one of the hens. They had seen them at 7PM and both seemed to be doing fine. I'm hoping that the one that died simply fell of the ramp or otherwise died of some other trauma but there were no visible signs on the body. A vet who I contacted online said it could be a viral disease that causes sudden death but again, I see no signs of it. Could it be that the Cochin just misses her coop mate or do you think it could be a disease? Hens in our other coop next to this one are doing fine and show no signs of any problems and were taken care of by the same neighbor.