Answer:
What travels from house to house and is sometimes narrow and sometimes wide but always stays outside?
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.
Break it and it is better, immediately set and harder to break again
I dig out tiny caves and store gold and silver in them. I also build bridges of silver and make crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs my help. Yet many people are afraid to let me help them.
What kind of room has no windows or doors?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.