You can take the cheap option or go all out with night vision.
I used the HW100KT .177 with a hawke night eye 4-9x50 IR zerod at 30 yards with a 70 meter deben stinger tracer with a red filter just a few nights ago and my mate had a BSA scorpion T10 .22 with a night vision scope zerod 10 yards. He shot 8 within an hour, i didnt even get chance to see a rat nevermind shoot one! It depends on your budget but night vision will always make a set up like mine look inferea, well it did the other night