Look toward the hole in the paper. Hold the flashlight near your face so that the light points at the hole in the paper. Look toward the hole in the paper. The light from the flashlight will reflect off the shiny bottom of the can, making the hole appear to glow. Take this discussion wherever you like, nocturnal animals, eye anatomy, etc.
Extension Give examples of other things that can be done along the same line here.
Resources Janice VanCleave s Play and Find Out about Nature .