Te specific study of the birds nest is calle "ornithology".
A birdhouse.
The nest was built by birds.
Birds mate after and before making a nest
It's called a cage.
Scientifically it's called "brood parasitism". The most well-known example of this type of birds is the Common Cuckoo. This is also the origin of the words "cuckold" and "cuckoldry".
The siblings in a birds nest are called a brood, and when a bird sits on her nest it is called brooding.
A nest, or a bird house.
A birdhouse.
Homes
They're called birds.
It was called the Birds Nest.
* A badger's nest is called a sett. * An eagle's nest is called an eyrie.
As birds, peacocks nest.
A nest, or a bird house.
a nest
A bird house is called a nest.
If the bird built it then it is generally called a nest. If it was made for the bird by a human it is generally called a birdhouse.