I have to do a demonstration speech for school. How can the people interact with my demonstration?

I'm doing a demonstration on how to set up a turtle aquarium. I have 2 baby snappers and im going to bring them in. I will let them hold them (im bringing handsanitizer) what else could they do or make.. I need something interactive.I have to do a demonstration speech for school. How can the people interact with my demonstration?
perhaps bring some long (READ: over a foot) medium sized sticks, and when the turtles get mad (because they will), and open their mouths, have the guests put the stick across the open mouth. the turtle will then snap the stick like butter, demonstrating just how powerful and dangerous their bite can be.