So I'm watching my young chick's forage when I notice that a few of my 3 month old chick's have what looks like a swollen breast. Almost like they swallowed a tennis ball. It is palpable and move able and manipulating it does not bother the chicks. I wonder it it's overeating or drinking too much. I noticed it in about 3 chicks. I will check tomorrow if there is any difference. Anybody ever experience this before?