My hen duck has laid 12 eggs up to now, and I keep them in her nest because I want to stimulate her go broody (if she goes eventually). I've read that I should keep between 15-20 eggs in her nest. If she reaches the number 20 for how long should I keep the eggs hoping that she will go broody? If she eventually doesn't sit on them, which of the 20 eggs should I eat? (average temperature around these period is 72F) When she reaches the number 20 will she stop or will she continue to lay eggs?