These friendly puppets will help you reinforce the concept that light is blocked by solid objects. Cut out the shapes and glue craft sticks to their backs. Shine a flashlight on them in a dark room and observe how their shapes block the light. Then, make the puppets even cuter by punching out some eyes. Children will be delighted when they see the eyes glow, as light (no longer blocked) streams through them. From Our Time to Learn, for ages 4-6.