Answer:
What's a place you have left but didn't enter?
People are hired to get rid of me. I'm often hiding under your bed. In time I'll always return you see. Bite me and you're surely dead.
I am believed to be only one dimensional, and tinier than anything can be, and there are many who say that I am the basis of all that we see. What am I?
Neither bought nor sold but more valuable than gold. It is built but not by hand. What is it?
Thousands lay up gold within this house, But no man made it. Spears past counting guard this house, But no man wards it.
The warmer I am the fresher I am.