Answer:
I spend most of my day eating white. When I am quick enough I get rewarded with fruit and something blue. In a dark room with blue walls I run from the ghosts that roam the halls
I wiggle and cannot see; sometimes underground and sometimes on a tree. I really don't want to be on a hook and I become a person when combined with “book”.
You use me from your head to your toes. The more I work, the thinner I grow. What am I?
I bring light to a dark world. In a current I travel and through tunnels I am hurled. Touch me and I'll kill you. What am I?
I have fangs and enjoy piecing holes with a single bite.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.