This guide is suitable for current RuneScape and Old School.
Head west of Varrock and speak to Gertrude.
She will tell you that she knows two people she would like you to meet, and directs you to the Varrock sewers. Make your way to the sewers and talk to Grimesquit. She will set you a task of catching 8 rats, and once completing that she will give you a rat pole and send you on your way to Jimmy Dazzler in Ardougne.
Head to the east of Ardougne near the wilderness lever, and speak to Jimmy Dazzler. He will slyly give you some directions to a mansion and ask you to get rid of the rats without being seen. Read the directions to be teleported to the mansion. Once in the grounds, the objective is to make it right to the back hiding behind the bushes without being seen by the guards. Should you be seen, you will teleported to the entrance and have to try again. Go to the west when the guard is moving to the north. Go north, and stand at the west side of the branch. Wait until the guards are both facing away and then go to the north. Eventually you will see a small hedge nearby a tree. Run to it and this will act as your 'checkpoint'. Be aware of the guards patrolling and look up the trellis to make sure it is clear before climbing up and entering the mansion.
Enter either of the side rooms, and wait for the guards to be a safe distance away before catching the rats you see running around. Climb down the ladders inside the rooms to find more rats and add them to your rat pole. Once you have caught them all, a message will appear saying you should return to Jimmy. Exit the mansion by teleporting out or retracing your steps, and return to Jimmy. He will present you with a book and grant you access to the kitten rat pits. He will then send you to Hooknosed Jack in Varrock.
Make your way to the south east of Varrock and speak to Hooknosed Jack. He will tell you that he is far too busy and will ask you to do a job for him; clearing a warehouse of rats. Give him the kwuarm, red spiders' eggs and an empty vial and he will make you rat poison. Head south and climb up the ladder and you will be in a room full of rats. Use the cheese with the rat poison to poison it, and then use it with the four rat holes around the room.
Now return to Hooknosed Jack who will tell you that his cat must have eaten a poisoned rat and has become ill. He will send you to the apothecary to the west. Give him the bucket of milk, marrentill and a bucket of milk and he will make you up a cure. Take this back to jack and he remind you that you haven't fully cleared the warehouse. You must kill the king rat with your cat. Pick up some fish to feed your cat during the battle and then head south to the warehouse. Use your cat with the hole in the wall and then a battle will ensue between the cat and the king rat. To heal your cat, use the food on the hole. Please note that if your cat is not successful, you will lose your cat and will need to get a new one.
Upon completion return once more to Jack and will grant you access to adult cat training rat pits, and will then send you off in the direction of Keldagrim to speak to Smokin' Joe.
Find your way to Keldagrim (the quickest route is by taking the minecart from the grand exchange). Head to the north east and around the pickaxe shop you should find Smokin' Joe. Speak to him and you will learn that his method of smoking isn't working and you will volunteer to do it for him as his lungs aren't what they used to once be. Use the weeds with the empty pot and then light them with the tinderbox and then use the smouldering pot on the rat hole. You will see that the rats are too quick. Try this again and your cat will offer to help.
Smokin' Joe will now grant you access to the overgrown cat rat pits. He will then refer you to The Face in Port Sarim.
Head to Port Sarim and by the fishing shop you will see The Face. Talk to her and she will tell you to speak to Felkrash down the ladder. Felkrash will offer you access to the pits if you can kill all of the rats in Port Sarim like she once did. Head back up the ladder and speak to The Face again and she will advise you to speak to Ali the Snake Charmer in Pollnivneach.
Once at Pollnivneach, make your way to the southern part of the town and speak to Ali the Snake Charmer. He will ignore you, so use some money on him and he will suddenly give you some attention. Ask him for help with the incentive of money and he will demand a price 1 coin over what you have. If you have the ring of charos(a) equipped, you can use the charm option to pay him 50 coins or else you can slowly start to walk away and he will give you a price of 100 coins. He will give you a snake charm and a music sheet. Return to Port Sarim and read the sheet of music.
Walk onto the docks of Port Sarim and click the play the snake charm. An interface will appear with 8 pages. You will have to play the right note (shown on the sheet of music) on each page. You will see a symbol at the top of the interface which will raise the octave. Use this on the fifth note. Below is a table with the correct page/flute. The < symbol represents the higher octave.
If done correctly, you will see a cutscene in which you charm all the rats in jumping off the dock. Speak to Felkrash once more and she will give you access to the final rat pits for wily cats.
Congratulations! Quest Complete!
Guide Made by: DaDa
Corrections submitted by: Deathslayer, DaDa, Yolk, Jei, Max, NotFamousYet, Power of Five