To answer this question baby ducks eat egg yolk, snails, earthworms and crustaceans. They also eat insects, invertebrates and insect larvae.
More Detailed Answer
The great thing about baby ducks (ducklings) is that they are born ready to travel and therefore have an easier time getting the foods they need to eat.
When they are first born they have a protective down covering and are also born with their eyes wide open as opposed to some other baby animals.
The first quest they will go on is with their mama to find food that is very rich in nutrients and they can sometimes travel for miles to find that food source.
It has been noted in studies that baby ducks have traveled as far as 3 miles away from their nest to find nutritious foods.
The good thing about baby ducks is that the first few days of their lives they don’t need to worry about getting food to eat right away as they get yolk sack nutrients while they are still within the egg.
For up to 3 whole days after they are born they can go without food.
Ducklings at this point will need a food that is rich in fat and protein. These types of foods will help the baby duck grow more quickly.
Some of the foods that are good for them to eat include crustaceans, snails and earthworms. Additionally they will eat insect larvae, invertebrates and insects.
Because of the protein rich foods they eat within weeks they will already look more like an adult duck.
If you have a duck that is domesticated then the best option for food is duck food which can be found at the local pet shop. As well as a snack ducks can be given small portions of vegetables and fruits.
As well the last thing is that baby ducks need plenty of clean fresh drinking water as well to be available to them at all times to help keep them healthy and grow.