What Am I Riddles

Question: Walk on the living, they don't even mumble.
But walk on the dead, they mutter and grumble.

What are they?

Question: Having one, means having something to follow. Once you question it, it means having none. People seek it, but some do and some don't find it. What is it?

Question: I come in many different colors. I create boundaries to keep things concealed and safe. My best friend is a lock and I am also made of different materials as well. I love to travel: you can find me anywhere. What am I?

Question: Light hides me and darkness kills me.

What am I?

Question: Look at me I want to play.
I'll move like you in every way.
Be tricky, but the result is always a draw.
Why? Because I'm an expert at response and call.

What am I?