I have a black polish hen who is just about 3 months old. About 3 weeks ago I noticed her acting a little funny (running really fast and bumping into things). She mostly keeps to herself but will come eat and sleep with my other 8 chickens. I picked her up and realized she won't open her eyes. If I pull the lids down, the eye looks perfectly healthy. There is no swelling or crustiness. She is eating and drinking and seems fine otherwise aside from keeping to herself... Any idea what is going on? I keep expecting her to start acting sick but so far, so good.