Answer:
I only exist when you are here. Where you never were I can never be.
I am the kind of fish that chases a mouse.
I always have to work with something in my eye.
I am what no man ever yet did see, which never was, but always is to be. What am I?
I love to twist and dance. Though wingless I fly high up into the sky.
The more of me you take, the more I appear behind you. What am I?