Outdoor Nature Hour: gross mold experiment

Two weeks ago, as part of our Outdoor Nature Hour assignment on mold, we took two peeled potatoes for an experiment on clean hands and dirty hands. We went around and touched things that we handle every day - the fridge, the toilet handle, door knobs, feed scoops - and then rolled the potato in our hands really well. We placed that in a jar marked "Dirty Hands Potato."
After washing our hands well, I dropped the next potato and it rolled under the dishwasher. I rinsed it off, obviously not well because the "Clean Hands Potato" grew some mold on it too.
The "Dirty Hands Potato," pictured at left, grew a lot more mold on it so we had a discussion about the importance of hand-washing and why bacteria like warm moist places.
Pretty gross, but it got the point across.