Sometimes you need visuals to drive an important point home; especially with kids. A teacher named Donna Allen did exactly that while showing her class how important it is to was to wash their hands.
On the left was a piece of bread she grabbed from a bread bag while wearing a rubber glove and put in a zip loc, in the middle a piece that she grabbed after washing her hands, and on the right one that she passed around the class and let the kids handle before putting it in the bag.
Fast forward a couple days, and boom! Point proven!!!
WASH YOUR HANDS.