What Am I Riddles

Question: While you're asleep You are also Awake, While you are Awake you're also asleep. What is it?

Question: I'm not dead i'm not alive, i'm not underground i'm high up in the sky, people speak of me but never saw me. Who am i?

Question: You can not eat me until you undress me. What am I?

Question: A cat,mouse,and dog all had an instrument,the dog had a flute,the cat had a trombone and the mouse's instrument bugs the dog.What was the mouse's instrument?

Question: (1) What am I and (2) how do you spell it?