Answer:
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair.
Brown I am and much admired; many horses have I tried; tire a horse and worry a man; tell me this riddle if you can.
When I point up, it's bright. When I point down, it's dark. What am I?
I am a tool for fairies.
I can point in every direction but can't reach the destination by myself. What am I?
Why was the cook arrested?