I have four chicks that are about a week old. One of them has 'runny bottom'. I don't know which one it is. They are all four running around and eating and drinking. I started giving them a little oatmeal yesterday when I realized it could get to be a problem. I put a little grit in it. It seemed to be helping but not so much today. I have watched them and can not determine which one has the problem or if it is more than one. Is this normal? I have kept the water fresh and have put in a teaspoon of apple cider vinegar to a quart of water.