Nature can throw a cruel blow to a nest of abandoned duck eggs if the mother duck has been shot by hunters or the nest has been disturbed. The likelihood is that the chicks will not survive. But if the eggs are still warm, there is still a hope of hatching them inside an incubator.
Check that the mother duck is not returning before taking the eggs. Cover the nest of eggs with something warm like a jumper or a coat. Pick up the abandoned nest and carefully carry the eggs home.
Check that the eggs do not smell. Throw an egg away if it does, as the unborn duck chick is dead.
Place the eggs inside an incubator to be able to control temperature and the humidity of the duck eggs. Borrow an incubator if you do not have your own so that the eggs have an increased chance of hatching. Make your own incubator, if this is not possible. Place the eggs into an egg carton and place the carton nest of eggs in a warm draft free area in your home like a cupboard. Place a heat lamp safely beside the nest to warm the area around the eggs, and remember to put a thermometer near to the nest.
Rotate the eggs daily a few times so that the fetus will lie on a different side each night, as advised by Duck Eggs. Fill a spray bottle with warm water, and spray the eggs with frequently to keep them humid if using your own homemade incubator.
Check your thermometer regularly to ensure the temperature is kept constant. According to Duck Eggs, the eggs should be kept at the temperature of 99.5 degrees Fahrenheit during the the first 25 days; and then during the hatching period, lower the temperature to 98.5 degrees Fahrenheit from the 26th day. Expect the eggs to hatch within 25 to 35 days, depending on the duck breed. Dispose of the eggs if they don't hatch after the hatching period.