Answer:
I always run but never walk, I sometimes sing but cannot talk, No head on which a hat to place, You always look me in the face.
Each morning I appear to lie at your feet, all day I follow no matter how fast you run. Yet I nearly perish in the midday sun.
My first master has four legs, my second master has two. My first I serve in life, my second I serve in death. Tough I am, yet soft beside. Against ladies cheeks I often reside.
This thing all things devours: Birds, beasts, trees, flowers; Gnaws iron, bites steel; Grinds hard stones to meal; Slays king, ruins town, And beats high mountains down.
Inside a great blue castle lives a shy young maid. She blushes in the morning and comes not out at night.
Both old people and owls are said to be possessing this trait