Question

birds built nests to​

Answer 1

Answer:

Although nests are primarily used for breeding, they may also be reused in the non-breeding season for roosting and some species build special dormitory nests or roost nests (or winter-nest) that are used only for roosting. Most birds build a new nest each year, though some refurbish their old nests.

Answer 2

birds built nests to breed.