Gotta get rid of the food.
Do you have any prime rodent habitat nearby that could be removed, like big brushpiles, old barns, etc?
We used to live on the edge of a protected "green space" so I used a metal mailbox with small side holes as a bait station. There was a board with 3 nails that held poison blocks and I would zip tie the door.
Blocks worked better than pellets because they stayed put on a long nail and were *much* more mold resistant.
I only had to clean & refill it once a month.
Since I used it long-term, I alternated between anticoagulant poison & another one that worked completely different.
If I recall, it was a chemical that gave the little fuckers cerebral edema.