get a cat.
As the cat is an obligated predator of rodants, the rats will smell the odor of the cat/cats you might adopt. I moved last year in an appartment that has rodants dungs in closets along wiht my cats and i never even heard one behind the wall ever since i moved in.
Cats will also give you unconditional love wich is quite the bonus !
No rats=no fear
EVERYONE IS HAPPY BUT THEM RATS