The night before last we were putting our birds to bed and the little group of dark cornish were leading us on a wild goose chase. It was a little later than usual and they seemed confused by the impending darkness and the new location of their tractor, about 20 feet away from where it had been the day before. There was a lot of running in the wrong direction and some agitation as we tried to herd them to their tractor where they sleep. In the middle of this exercise, one sat down abruptly. We picked her up and put her in the tractor, and within a few minutes she was joined by all her buddies. Yesterday morning when we opened the door, everyone ran out but her, she just stood in the corner. Since she was acting so strangely, I put her in a 10 x 10 pen by herself in case she was sick. Last night we brought her inside. She is an 11.5 week old dark cornish. She free ranges during the day but has free choice organic starter/grower at several places in the yard and plenty of fresh water. Since she sat down during the chase to bed, her poop has been liquid and mostly white. She is eating and drinking a little. She mostly stands, hunched over, although I did see her sunbathing yesterday once. None of the other birds seems ill, we have dark cornish, red broilers, and buff orps who all free range on our two acres but sleep in different places. I'm thinking maybe she had a little heart attack. I know heart problems can occur in the cornish cross, but this breed is much more active (more active than any of the other breeds we have) and they forage (lots of pasture and veggies) for much of their food, so I didn't think they were susceptible to those kinds of problems. They say a picture is worth a thousand words: What do you think?