Why do birds build nests?

Birds live in nests. They sleep there like we humans do in our homes. Many birds raise their young in their nest. The mother lays her eggs in the nest and then she incubates the eggs there. Sometimes the father bird also helps make the nest cozy and warm with feathers and moss.

Most birds build their nests high up in the trees. Predators such as squirrels and martens then can't get to the eggs as easily. Storks don't like to build their nests in trees. They prefer high masts or chimneys.

Geese and ducks are waterfowl. They build their nests on the banks of rivers or lakes. Masters at building nests are the swans. They can build nests that float on the water like small islands.

In a nutshell.: Birds live in their nests, they raise their young there, and that's why they build their nests in safe places.