They rip hair off and coat the nest with it. Then they will give birth. Sometimes, though, they have a false pregnancy when they are close to male hormones and pretend they are pregnant. Within a week of building the nest they will usually give birth if they are, in fact, pregnant.
A Cukoo Bird builds it's nest in a chimney
nest
The Weaver builds a nest out of grasses, with the entrance at the bottom.
A peacock builds a nest out of branches.
an eagle builds a nest called an aerie
if you like bird feces
Kingfisher builds its nest in banks near the water.
termite
skylark
the female
The bird that builds a nest that looks like mud is called a mud dauber wasp.
nothing :)