Couldn't quite figure out how to phrase this question so it made sense. At this point, it's just hypothetical curiosity, but still I wonder... Chicken eggs take 3 weeks to hatch, correct? What if I have a hen that goes broody a week before I put fertile eggs in the nest for her to hatch? Will she continue to sit until the eggs have hatched (can she know how far they're developed?) - a total of 4 weeks - or will she get off a week early? What if it were two weeks difference between the time she started sitting and when eggs were placed in the nest (a total of 5 weeks sitting)??