Answer:
What runs around the whole yard without moving?
When young, I am sweet in the sun. When middle-aged, I make you gay. When old, I am valued more than ever. What am I?
I make a loud sound when I'm changing. When I do change I get bigger but weigh less. What am I?
Break me and I am better immediately set and harder to be broken again.
I hide but my head is outside. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.