We got 6 chicks two weeks ago. Yesterday my son brought one of them in saying his leg wouldn't work. I checked him out and he could stand but was doing something weird with his mouth. He stretches his head forward and opens his beek like he's crowing or something but nothing ever comes out. He just stands there, not moving, doing that thing with his head every 2-3 seconds. Any idea what the problem is or how I can help it?