What is the best way to kill a mouse?

One summer, I went for a visit to my grandmother's island and discovered the place had been infested with mice. They'd come on a fishing boat and gorged themselves on coconut. So how do you get rats off an island? Hmm? My grandmother showed me. We buried an oil drum and hinged the lid. Then we wired coconut to the lid as bait and the mice would come for the coconut and... they would fall into the drum. And after a month, you have trapped all the mice, but what do you do then? Throw the drum into the ocean? Burn it? No. You just leave it and they begin to get hungry. And one by one they start eating each other until there are only two left. The two survivors. And then what? Do you kill them? No. You take them and release them into the trees, but now they don't eat coconut anymore. Now, they only eat mouse. You have changed their nature.