Answer:
Sometimes black, sometimes white, I have veins but no blood
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 word is a plural, but when you add an "S" to the end, it becomes singular?
Give it food and it will live, give it water and it will die.
I drive men mad for love of me. Easily beaten, never free.
Sometimes I am white, sometimes I am dark. Most people love me. What am I?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?