Answer:
What room do ghosts avoid?
What has many teeth but can't bite?
I shift around though always slowly. I never move more than a few inches at a time. A large movement by me can kill many people. I am huge yet unseen by humans.
My first is in riddle but not in little. My second is in think but not in brink. My third is in thyme but not in time. My fourth is in mother but not in brother. My last is in time but no t in climb.
I am commonly ate before I'm born and after I'm dead.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.