Answer:
They're up near the sky, on something very tall. Sometimes they die, only then do they fall.
I am black when I am clean and white when I am dirty?
The barber of New York shave all men in New York. No man living in New York is allowed to shave himself. The barber of Nee York lives in New York. Who shaves the barber ?
A little house full of meat, no door to go in and eat.
A word I know, six letters it contains. Subtract just one and twelve remains.
It's what light turns into in the night