Have you ever poked something through a balloon? 

On the 17 -11 – 16 Room 2 tried just that with some kids succeeding more than others. 

First we blew up our balloons to the size of around three fists and tied a knot. Then we pushed a kebab stick through the bit of the balloon that was not stretched and out the other end.   The balloon should not pop because the unstretched bit of the ballon grasps tightly around the kebab stick. When I began this experiment I thought that the balloon would. Pop.    But now I understand that the non stretched part of the balloon concealed the hole around the kebab stick.