They are great hunters and natural rat predators. You will still be killing the rats indirectly but it won’t cause them great pain. This is just a way of initiating the natural cycle. A good cat will clean up your rat infestation in just a few weeks. Just remember a cat will not be able to catch a rat that is in the attic or behind a wall. You will know where they have been by rat droppings you notice or by the holes chewed in walls, food boxes, insulation and other places in your home. This is where you’ll want to leave the traps. You can purchase these from hardware stores and other retailers if you decide you want to kill the rats. Be aware that rat poison does not kill a rat instantly, it can take up to a week to kill the rat. The rat will be in immense pain during this week, so keep that in mind.  Read the instructions and cautions carefully. Most rat poisons include warfarin, which causes internal bleeding and other drugs that kill rats, but can also be harmful to pets and people. Check the traps regularly. A rat corpse will give off an unpleasant odor if you do not remove it immediately. Traditional snapping traps are much more humane than rat poison, as it should kill the rat immediately. However, in some cases it can only severely injure the rat, in which case you should put it out of its misery. These are flat, sticky pieces of wood that trap rats until you can remove them. Once again, make sure that you only set glue boards if you intend to kill the rats. These rats are not going to survive, as there’s no way to get them off the glue board. Some rats will chew off their feet or legs in order to escape from the trap and others will get their head trapped in the glue and suffocate. It is not the most humane way to get rid of rats but it will work. If you find a rat in a glue trap that has not been killed, you'll have to stomp on it with a boot to kill it. It's either that or hitting it on the head with something hard like bat. Do whatever you can stomach and then toss the rat in an outdoor trash can.

TL;DR in Indonesian:
Pelihara kucing. Kenali tempat makan dan sarang tikus. Tempatkan racun tikus atau jebakan tikus klasik (jepitan) di area yang sering didatangi tikus. Gunakan papan lem tikus untuk membasmi tikus.