Today in my 7th grade life science class we made models of our digestive tract using long pieces of plastic tubing. Upon seeing a student lift up the end of the model and put it to his mouth to inflate it with air, I smiled and said:
“Please don’t blow into your rectum.”
Heh heh heh. Who’s the middle schooler now?
Ideas In Things 
You’re the best! Truly. This made my day.
Mindy