Probably clean up discarded biological matter pretty well. Rats have decent cognitive capabilities. I wonder if trained cleaning rats would displace the naughty variety.

https://www.theguardian.com/environment/2022/feb/01/swedish-...

Wild rats aren't naughty. They're just animals trying to make their way in the world the same as the rest of us. But they do make a mess and carry diseases, again maybe the same as the rest of us lol.

Agreed, my use of “naughty” is to acknowledge that rats in a relatively natural state have some characteristics deleterious to close human habitation.