Yesterday I didn't get any eggs, and I noticed they had pushed aside half their bedding into a pile. I dug around loosely to see if they had accidentally gotten buried, but I didn't see any. When I pulled away the chickens pushed all of the bedding back in place, but I thought they were just rooting for spilled feed. Today I dug around more, and found two eggs berried deeper that I had dug the day before. They weren't too happy when I took them, but they didn't fight or peck me. Why are they doing this?