Half of my flock, 5 hens, are down. I have been on nite shift for several days and the wife has been taking care of them so I haven't seen them lately. It's like they just don't have the energy. All 5 are in the coop and should be outside the pen free ranging now. 4 are laying upright, heads up and looking around but not getting up, moving around and the other is alive but head down and shallow breathing. Any ideas? Should I move the alert ones outside in the shade for fresh air?