How easy is it to control a broody mothers clutch size? I've read some threads saying they might choose to sit/collect up to 10-15 eggs at a time. If I wanted say... 4-5 ducklings. Can I just let her go broody with 5 eggs, mark them, then remove the new (unmarked eggs) each morning after that until she stops laying and tends to the 4-5? Some people have even suggested replacing excess eggs with fake eggs? Is that necessary? Also, will disturbing the nest turn her away from going broody?