I am new to the board and need your help. I orderd 25 chicks from MMH and they are about 5 weeks old. I recently put them in a run because I need my brooder for another 36 chicks coming tomorrow. My first order consisted of Rhode Island Reds and Brown Leghorns. I went out today and noticed that the all had a very noticeable, hard knot on the right breast. What is wrong?