How long will the mother duck leave her eggs?

After she starts laying, she will produce an egg or two a day up to 10-18 eggs. These eggs will be left uncovered until she is ready to "sit" When she has laid the eggs she will start sitting on them all day long for 28 days (most breeds). She will get off the nest for up to 1/2 hour each day after she has started sitting, so she can eat, drink and bathe. Her being wet when she comes back to the nest is important in the process of her maintaining the proper humidity of the eggs.