If you handle anything that has rat urine on it, wash with a light bleach solution, hands too. This method can also be used to delete the rats:-) Up to you.
One time we released a rat in the woods and it ran 10 ft out then ran back into the container. I went deeper in the woods and let it go again. The rat darted into the woods and was climbing a tree when a hawk came from nowhere and grabbed him. The bird flew off into the sky with the rat.
This container works well, you can use any container with a screw lid, just make sure it is not glass. Glass is yew heavy and if you get more than one, the rat in the container can roll the heavy glass container over other rats out side and crush them. Opaque containers work better, I used clear so you can see the rat.
Any plastic container that is deep and has a screw lid will work. This is a 50 gallon drum, a deep garbage can will work too. They can jump high so make sure it is at least 40 inches deep.