Rats

[Mortblanc]

If you set out the poison and offer water at a point outside, the poisoned rats will generally go to water after ingesting the poison and die at the water source.

I have only had on severe rat infestation at one location I moved into 30 years ago. It was a rural area and the rats had replaced squirrels in the ecosystem. They were living on forest mast and nesting in the trees. It took me several months to poison and shoot out the population.