Meaning: The birds were flying back to their nests to sleep for the night.
Choice of Words: Birds flew means the birds were flying. Home they went means the birds went to their homes.
Alternative Expressions
The birds took to the skies and returned to their nests.
Meaning: This sentence also means that the birds flew through the air and returned to their homes, but it uses different words to describe the same actions.
Choice of Words: The phrase "took to the skies" describes the birds flying into the air. "Nests" are the homes where birds live.
With graceful wings, the birds soared high and then descended back to their abode.
Meaning: This sentence uses more descriptive language to describe the birds' flight and return home, but it still means the same thing.
Choice of Words: The phrase "with graceful wings" describes the birds' elegant flight. "Soared high" means that the birds flew up into the air. "Descended" means that the birds came back down to the ground. "Abode" is a fancy word for home.