The most challenging thing in this world is learning the best way to kill rats. Although most might say this is an exaggeration, just think about it. Throughout centuries, they still thrive. Nobody, even nature itself, has eradicated rats. Until now, no one could say that he or she has mastered the best way on how to kill a rat.
The best way to kill rats would be through poisoning them. There are a lot of ways on how to kill rats nowadays through giving poison, and poison has different kinds of chemical components that can be found in the market easily. Poisoning is very effective because it kills in numbers and it is not hard to set up. You just have to be in the right place at the right time. With proper bait, timing, and set-up, you will surely be able to kill them.
A negative point about rat poisoning is that when the rat dies, it stinks and sometimes its remains are in their hole. The corpses are never easy to clean. As they rot, things just get worse and you cant do anything about it except for wasting a lot of air freshener. But nevertheless, poisoning them is still a very humane and easy way if you want to know how to kill rats.