When I was a kid in Iowa me and my buddy would always explore along the creeks and rivers. One time we came on to one big snapper. It's head was about as big as around as a plastic 2 liter soda bottle. We'd get a branch and tickle it's nose and in a flash that turtle would snap the end of that branch off in the blink of an eye. It almost looked like it was having fun showing us how mighty it's jaws were.