Go into a dark room and chew up a few Wint-O-Green LifeSavers while looking in the mirror. (This is one time when it's okay to chew with your mouth open!)
Can you see the flashes in your mouth?
Crunching the candy breaks the sugar crystals and builds up opposite electrical charges on the pieces. Electrons jump between the pieces, colliding with nitrogen molecules to make invisible ultraviolet (UV) radiation. The candy's wintergreen flavoring absorbs the UV radiation and re-emits it as the spark you can see. It's science in your mouth. Try it!