I have Buff Brahmas, and the past few days when I have gone to collect the eggs I have noticed that one of the eggs in each batch is cracked. It has a good thick shell, but looks more like a pecked egg to me since the crack is in the shape of a circle. Is it possible that one of the hens is doing it? Or could it just be a coincidence? They are all laying in the same box. There are 4 hens, one rooster, and 3 young Americaunas in the coop. Thanks for the help.