The term "nest egg" refers to ones financial savings for retirement.
When a bird feathers its nest, it lines the nest with soft feathers. The idiom means to make your life comfortable by earning more money.
It means that the egg is not useful any more. If in it was a bird or duck or somthing, it means that it is dead.
"An egg bank contains frozen donor eggs, used for reproduction. A nest egg is typically an accumulation of money used for retirement. Therefore an egg bank is not the same as a nest egg."
The idiom means impress someone is egg on
It doesn't mean anything more than the fact that one animal or bird laid an egg and it'll probably hatch some day...
Farmers used to leave one egg in the hen's nest to encourage her to have more eggs.
A cuckoo does not make a nest, a cuckoo will lay an egg in another birds nest, the other bird will then care for the egg and chick as if it was it's own.
egg
N.E.
the nest
Some reptiles lay egg in the nest and some reptiles lay egg on the land.
the mother bird will not come back to the nest, and will just leave the egg there.