Answer:
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
What two things can always see what the other sees, but can never see each other?
We are all around, yet to us you are half blind. Sunlight makes us invisible, and difficult to find.
You use it between your head and your toes, the more it works the thinner it grows.
What is lighter than what it is made of?
What language does a billboard speak?
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?