How do you get the bullseye achievement on insectonator zombie mode?

To achieve the Bullseye achievement in Insectonator's zombie mode, you need to kill a zombie with a precise shot that hits a specific target area, usually the head. Aim carefully and try using weapons that allow for pinpoint accuracy, such as the sniper rifle or throwing knives. Utilizing upgrades and power-ups can also enhance your chances of hitting the target directly. Practice timing and aim to improve your chances of landing that perfect shot.