Britannica Sources used in this answer

Why do birds build nests?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A zebra finch (Taeniopygia guttata) with a bright orange beak, gray head, orange cheek patch, and black-and-white striped tail perches on a branch. — Bird A brightly colored zebra finch (*Taeniopygia guttata*) perched on a branch.

Birds build nests primarily to provide a structure for laying their eggs and to house their young. While some species utilize simple scrapes in the ground or natural holes, many birds construct elaborate structures using materials such as twigs, leaves, mud, feathers, and spiderwebs to create a safe environment for their offspring.12

These nests serve as a critical site for incubation, allowing parents to keep eggs warm and protected until they hatch. For many species, the nest remains essential after hatching, providing a place where altricial young—which are born helpless and without feathers—can be brooded and fed until they are capable of regulating their own body temperature and eventually flying.2

It is important to note that not all birds build nests; for example, some penguins incubate eggs on their feet, and brood parasites like cuckoos lay their eggs in the nests of other species.2