Answer:
Not born, but from a Mother's body drawn. I hang until half of me is gone. I sleep in a cave until I grow old. Then valued for my hardened gold.
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 know a word of letters three. Add two, and fewer there will be!
What runs around all day. Then lies under the bed. With its tongue hanging out?
A house full, a yard full, a chimney full, no one can get a spoonful.
What sphinxes employ and players enjoy.