My 15-16 week old BO pullet, Pearl, is acting a little under the weather. She is very lethargic, carries her head tucked close to her body and her tail down. She's still eating and drinking, but not with great enthusiasm. Today I noticed a small amount of runny greenish poo on her bottom (a few drops). When I visit their yard, she will come out to visit me, but long after the other six are running around me begging for treats. She seems to want to stay in the coop, huddled in one of the nest boxes. I put a dish of feed and some water near her to encourage her to keep eating and drinking but I don't know what else to do. I would appreciate any advice.