I have six hens 16 weeks in age (two easter eggers, 1 gold-laced, 1 New Hampshire red, 1 Sicilian buttercup, 1 Dominique). They are generally quite active, but recently they do not have the same amount of energy. Their coop is two story, enclosed in the top and grass at the bottom. Generally they spend all day pecking, eating grass in the lower level, for the past few days they have stopped. They only come down for a few minutes to eat or drink, then go back up. I'm not sure what is going on...they don't look sick.. any advice would be great.