The video below provides a great demonstration for how to show kids how easily germs spread.
You will need just a couple of items to do this demonstration:
The Glo Germ powder is a safe way to simulate germs. Like germs it cannot be seen. “Infect” one or two people with the Glo Germ powder. Then check the area and other people with the black light later and see how the “germs” have spread.