We are not alone. We share our planet with trillions upon trillions of microorganisms. They are truly everywhere.

To illustrate this point, and to show students that, perhaps, parents are correct in insisting that hands be wash at least occasionally, my students took organism samples of various objects around the school using cotton swabs and petri dishes. Within days the petri dishes containing blood agar started to reveal what was once invisible to the human eye. Colonies of microorganism rapidly engulfed the agar, and showed my students that we share our world with countless invisible organisms. In the immoral words of one of my students, "Mr. Graham, that's really gross!"