Why don't woodpeckers get headaches when they slam their head on a tree all day?

If someone owns a piece of land, do they own it all the way to the center of the earth?

If an escalotor breaks down, does it become stairs?

Why do they say a football team is the 'world champion' when they don't play anybody outside the US?

Do stuttering people stutter when they're thinking to themselves?

If you put a chameleon in a room full of mirrors, what color would it turn?