Answer:
What has 4 legs in the morning, 2 legs in the evening and 3 legs in the night?
What's as small as a mouse but guards a house like a lion?
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.
I cost no money to use, or conscious effort to take part of. And as far as you can see, there is nothing to me. But without me, you are dead.
I am whole but incomplete. I have no eyes, yet I see. You can see, and see right through me. My largest part is one fourth of what I once was.
When is it bad luck to see a black cat?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?