I went to the coop yesterday and one of my Bantam hens was lying on her side on the ground. She is alert, eating, drinking, pooping, preening. Everything works except her legs. She can move them but it seems she has no control. She is about two years old and has raised a few clutches of chicks. When I try to set her upright she falls over. Internet says it may be nutritional. The hens are on scratch grains (mostly corn) for the winter. I have fed her scrambled eggs with the shells and chick starter but she seems the same. She is warm in my kitchen. She now has free choice eggs, oyster shell and fresh water. Help-I love my chickies. All other chickens seem just fine. Any advice?