I have a 9 week old Black Australorp pullet who was fine yesterday but today I found her hiding in a nest box fluffed up. I picked her up and noticed she had an empty crop and was very skinny. She is drinking a lot of water but only a tiny bit of food. She wont get up and walk, and looks pale and miserable. I recently moved her and 30 other chicks into the enclosure with my grown hens. She had been going out and scratching, eating and having a good time. The poo is bright green and watery. I have her inside in a dog crate now with water and food. Gave her Nutradrench and started her on Corrid just in case. She has no mites or injuries that I can see. Any idea what might be wrong with her?