If you’re a parent or a teacher, you probably say “wash your hands” more than any other phrase. Chances are, the kids in your life just don’t understand why hand-washing is such a big deal. Well, here ...

He used a powder called Glo Germ, which, like real life germs, is invisible and spreads from surface to surface through contact. Unlike germs, however, it can be seen under a blacklight, enabling ...