One of my ducks has been setting for approximately 4 weeks and I'm anxiously awaiting the arrival of new ducklings! My question has to do with warmth. It is now August and the temperature drops to about 16 degrees Celsius at night. Do I need to provide a heat lamp for the ducklings or will mama duck be able to keep them warm enough by herself? Also, another duck has just begun setting yesterday and her babies will hatch in September, which will bring even colder nights. Her nest is outside of the duckhouse. Will I have a problem with warmth then or again, should mama be able to take care of that herself? Thanks!