Unlike adult ducks, ducklings do not have waterproof down. An oil gland near the tail of adult ducks provides the waterproof cover. Ducklings get some waterproof covering from their mother's oil gland, which helps to keep their body temperature steady and helps them avoid drowning. After about two months, ducklings have feathers that enable them to fly, thus becoming independent.
In the wild, duckling mortality is higher in the first 10 days after hatching. The main factors that affect duckling survival include cold weather, lack of food, parasitic diseases and attacks from predators. Young ducks are vulnerable because they cannot fly away or swim fast enough to scape predators, such as largemouth bass, northern pike and other big fish, bullfrogs, snakes, snapping turtles, foxes, raccoons, hawks, owls and herons.
The size of a duckling depends on the species, but it is true that larger eggs in a clutch generally produce larger ducklings. They can feed themselves when they reach the water, but they need to learn what is edible by observing the mother. Like adults, young ducks feed mainly on small insects and tadpoles, aquatic plants and grasses.
Ducklings younger than 10 days tend to swim and walk as a group, always close to their mother, to avoid the attack of predators. Ducklings first recognize their mother's calling sounds, in their first days after hatching. Visual recognition is also important, but happens only later. As in other birds, in ducklings the auditory system develops before than the vision.