One of our Buff Orpington broody hens is killing newly hatched chicks. This is her 2nd time doing this - the first time I just thought she made a mistake since she was a new mama. This time is not a mistake. As soon as chicks hatch (still wet) she kills them. If given fluffy, dry chicks, she does fine. What causes this? Is there any real solution to this besides taking the eggs from her a few days before the hatch and putting them in an incubator then giving them back?