Answer:
What has roots as nobody sees, is taller than trees. Up, up it goes, and yet never grows?
Who is he that runs without a leg. And his house on his back?
What breaks on the water but never on the land?
What gets closer when you blink?
What has a bell but isn't a church. Is full of air but is not a balloon?
I have two bodies joined together as one. When standing still I run and run.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?