You need to acquire a good sized rat snake.
There is NO other solution better than that.
I don’t care how clever the rat is, the snake will find it.
For *years* we had a rat plague because locals killed every snake they saw and I went every route imaginable to get rid of them, to little avail.
They ran through the walls with impunity and disregarded all my “brilliant” efforts to kill them.
Then a nice guy dropped off a rat snake he’d caught and surpringly soon, no more rats.
It slithered into the walls as well and the rats were no match.
The spring that he gave it to me, it was just a small snake and I scoffed at the idea of it eating my Ratzillas.
This spring, it had quadrupled in size, having feasted on my plague.
Nature always trumps any of our pitiful efforts.
We think alike. Thanks!