I sometimes watch these videos of people, usually in England, shooting rats as a form of pest control.
see:
*click on the link the screen gives you to view, where it says "watch this video on YouTube," as the owner disabled viewing from remote locations*
As it is quite difficult to own firearms there, many guys who would otherwise buy and hunt with 30-.06's and the like are relegated to air rifles only.
Curious, I looked into the sport and there are some very accurate, powerful and expensive air rifles, sights and accessories available.
Head shot, baby: head shot.