Thanks everyone for your suggestions. Surely it couldn't have happened this fast, but I am pretty sure that I have broody Buff Orp hen!!! I hadn't tried your suggestion yet, Ed, but I did put boiled eggs in the nest. This hen had been making the noises that disturbed/anxious chickens make, especially broody hens with chicks. But she hadn't been staying on the nest, so I just assumed that it was a rooster, dog, or even me that was making her a little nervous. But it may be that I was just gathering the eggs to quickly, and she was just waiting for something to set on. Now she is sitting tight in the nest and has been for about 2 hr., and any time I get close to the nest she puffs up her feathers and squawks at me really loud. I am so excited, I really hope that she is broody. If she is still on the nest tonight, I am going to isolate her and her nest and give her a few eggs! Woohoo!