A practice pioneered by a small but evil kid at my school. He would stealthily creep up to someone enjoying their sandwich or chocolate bar, snatch it from them, and then proceed to cram it into his mouth with an expression of evil glee on his evil fucking face.

This continued until the day when Russel, much to his dismay, dropped a virgin Topic bar on the ground.
Inspiration struck me. I searched for and found a dog turd, and dipped the Topic into it, giving it slightly more than a hazelnut in every bite. We then waited until the inevitable swan-dive. Revenge was very very sweet.

The evil kid had the gall to complain to the head of year about this. I explained to Mr Cooper that I had just instructed Russel to dispose of his dogshit-encrusted Topic into the bin lest any young children or animals think to eat it when the swan-dive occurred. Despite Mr Cooper's huge grin and barely stifled laughter, he appeared to believe me.