How about another predator that isn’t at pet? An owl maybe?
https://www.birdinformer.com/how-to-attract-owls/
I could see you giving a pass to 1 or 2 rats but if there aren’t predators, you could end up with them taking ownership of your garage. Then they’ll learn how to wrench and turn your 911 into this.
Then they’ll learn how to drive and they’re off to NIMH.