Two men are in a desert. They're both wearing backpacks. One of the men is dead. The man who is alive, has his pack open. The dead man's pack is closed. What is in their packs?
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 am I?
