Answer:
What do you have when you're sitting down that you don't have when you're standing up?
Lovely and round, I shine with pale light, grown in the darkness, a lady's delight.
When the horse strokes the cat, the wood begins to sing.
What can be seen but never found that only hides in the unwound?
I am black when I am clean and white when I am dirty?
Those with eyes bigger than their stomach will definitely leave the restaurant with one of them. It is named after a house pet as well.