Answer:
What binds two people yet touches only one?
I fly through the air on small feathered wings, seeking out life and destroying all things.
What kind of room has no windows or doors?
I am the heart that does not beat. If cut, I bleed without blood. I can fly, but have no wings. I can float, but have no fins. I can sing, but have no mouth.
I have four wings but cannot fly. I never laugh and never cry. On the same spot always found, toiling away with little sound.
You use it between your head and your toes, the more it works the thinner it grows.