Squigly Squigly's Brain Teasers

Question:

What moves forwards and backwards but has no legs, it cannot talk, it cannot walk, it doesn't slither or crawl across the floor either. It comes in different shapes, sizes and colours. What is it?

Answer:

A door.

Try another Brain Teaser:

He who builds me doesn't want me,
he who buys me doesn't use me,
he that uses me doesn't know he's got me.

What am I?