Good Riddles

Question: Two criminals, Rob and Stan, are thrown into jail. But they plan to escape. There is a open window twenty feet off the ground. They try and try but are never able to reach it. They decide to dig their way out instead. After months of digging, they come up with a much easier plan. The plan works and they escape.

What was the plan?

Question:

The dirtier I am, the whiter I get,
Leave a mark on me when you stand, I'll leave a mark on you when you sit.

What am I?

Question: Shake me and I'll do what you want,
but first you have to pull me from the ground.
I'm on the tip of your tongue and over your shoulder.

What am I?

Question: We are twelve in the family. I am the second one, as well as the youngest.

Who am I?

Question: What can you see but not hear?