A nest is where a bird lays and incubates its eggs and raises its young.

There is a wide variety in the kinds of nests that birds make. The simplest is just a shallow scoop made in sand. Another simple nest is to make use of a fork between branches in a tree, or a natural hole in the trunk. Other birds dig burrows in river banks or drill out holes from tree trunks. Some use mud and saliva to make nests high up under eaves of roofs.

The smallest bird nests are those of hummingbirds. They are 2cm across. The largest nests are mounds built by brush turkeys and are over 11m across.

Not all birds build nests. Cuckoos, for example, lay their eggs in the nests of other birds. Some just use rocky ledges.

Most birds build a new nest each year, but birds like pigeons often reuse their old nests. Storks are well known for reusing their large nests.

The female is the main bird that builds the nest, although in the case of the weaver bird, the male builds the nest as part of his courtship.