I have a silly question. Does a Broody hen need to be broody for a certain length of time? I have eggs in the bator due to hatch on 10/11. My Cochin Sylvia started her broodiness (crabbiness) on Saturday the 26th of September and started actually setting on September 30th. I would love to slip the bator eggs under her and let her finish the clutch hatch. So does her body need to be broody for 3 weeks, or if the eggs hatch early will her broody break? If I give them to her now, she would have been sitting on them for only 9 days -- 11 to 12 days into her broody cycle.