Brother's New Trick

In the car on the way home yesterday:

Brother - "I can talk and say stuff without any sound."
Mommy - "You mean by using your hands, like sign language?"
I was thinking that he was learning something new in school...
Brother - "No, without my hands. Watch."

Silence...Silence...

Brother - "See!"
Mommy - "Wow, I didn't hear anything!"
Brother - "I was saying, LOOK OUT FOR THAT BIG TREE OVER THERE! Now I will do it with my mouth closed!"

This new trick could come in handy...