Answer:
I fly to any foreign parts assisted by my spreading wings. My body holds an hundred hearts Nay I will tell you stranger things when I am not in haste I ride and then I mend my pace anon.
I dig out tiny caves and store gold and silver in them. I also build bridges of silver and make crowns of gold. Sooner or later everybody needs my help yet many people are afraid to let me help them.
I have hundreds of ears but cannot hear a thing. What am I?
I am often sold by children entrepreneurs in summer time
lighter than feather and softer than silk yet the strongest man in the world cannot hold me for more than a few minutes.
No matter how little or how much you use me, you change me every month.