Good Riddles

Question: I can fly in your mind. I was not made to scare anyone, but many fear me. What am I?

Question: What goes round the house and in the house but never touches the house?

Question: What is brown or silver, has a head and tail but no arms or legs?

Question: Everyday I stalk you all day long,
With every move you make, I never make one wrong.
I vanish twice a day with the sun's height and fall,
I will follow you anywhere,
even the bathroom stall.

What am I?

Question: I can be sun,
I can be sand,
and I can be bird.

What am i?