I've seen many posts regarding inspecting chickens' crops. Well, I can tell it's full by it poking out in the afternoon/evening. I can tell it's empty looking in the morning because it's not poking out. What else am I supposed to check on regarding the crop? What is it supposed to feel like (for the ones I can easily catch)? How do you know if they have sour crop & such? What all can you tell about a chicken & their crop by inspecting it & what are all the ways to "inspect" it?