I have 2 plymouth barred rock hens (total hens are 5) and they seem to be the only ones doing this - after they lay their eggs they peck at them and make holes in them! I am a new chicken owner and new to this site. I have tried placing fake pullet size eggs in their nesting boxes, but this has not worked. They are all about 5 months old and are all laying! Any help would be greatly appreciated! Thanks in advance.