We use the black bait station with 2 access holes. We use block poison because generally they can't drag that off. We put the bait station out of reach, often husband will cover it with boards or bricks.
Every fall we generally need to deal with rats as they are coming in from the fields to...
Poison in a covered bait station should take care of all your rats. They should mostly die in their tunnels. Poison is the only thing that works on rats here. They say if you are seeing rats you have hundreds, so it will take a bit of time to kill them all.