I use the same system in my basement using 5 gallon buckets to eliminate mice from my house. It works great.
Regardless of the size of the rodent, the system works. Ya'll just need a bigger bucket for bigger rats.
got a drawing for the rest of us?
Explain the system we need help.
"Silva: Do you like my island? My grandmother had an island. We could circle the whole place in an hour. Then one day, we went back to the island to see it infested with rats. They came from a sunken ship and fed on coconut. But my grandmother came up with a solution. She buried oil drums and hinged the lid with coconut for bait. In about three months, all the rats were trapped. So what do you do? Do you drown them? Burn them? You leave them alone. As soon, they begin to eat each other.
And when there are two left, you let them go back into the the trees.
But they will not eat coconut anymore.
Now they will only eat rat.
You have changed their nature."
I used the same system in the mid 60s to get rid of the mice in my brother’s shop. Worked like a charm.
I got the idea from reading about the old sourdoughs in Alaska using the system to get rid of shrews. In their case, the shrews became bait for more shrews, since they are cannibals.