I am new to this with my chicks only 7 weeks old. They have been doing really well and growing great! But I notice that they all seem to have a lump down low on the next and near to the breast. Is this just the crop? I have 10 birds so I really cant tell them apart yet. It seems they all have it but some really big (size of nearly a golf ball) and some are smaller. I always pet them on the front and sometimes you can even see it, seems like them are lopsided on the front. They are all eating great, pooping like crazy and none of them are lazy or anything like that. I am thinking this is just when they eat and the crop fills up and thats what I am seeing? They have gravel available at all times, and I have been adding extra into there food when I feed them, just a FYI. Thanks!