Epidemic
Using "Glo-Germ" lotion, which contains bacteria sized bits of plastic which glows under ultra violet light, we did activities to show how diseases spread, and how vaccines protect us. Then we put the lotion on our hands and tried to wash it completely off following the hand washing instructions posted over our sinks. Some could do it in one trip, some in two, and some needed three trips to get all the "germs" off!