about three or four weeks ago, one of the 1 and a half month old chicks was free ranging with teh others, and then started hobbling. then it started walking strait up right like a duck. it hobbles, it's legs pulled back so it walks strait up right with it's butt resting on the ground. at first it held it's wings out as it did it but now it doesn't. the bird eats and drinks fine. It can fly up onto things, but it continues to walk oddly. now, a 2 and half month old chick is doing the same thing. gradually at first , but now, doing the same hobbling upright walk with it's butt resting on the ground like a human walking in a crouching position I have check the legs and they seem to be stiffly positioned into a backwards crouching position. It is very odd. I have never had this happen before. does anyone know what it could be?