After a discussion in Nursery, one of our children brought in a pack of balloons.  Mrs Bruchez had been talking about papier mache and how to make it.  As she started to demonstrate, some air escaped from the balloon, much to the amusement of the class.  It turned into 5 minutes of pure joy and hilarity as we watched the balloon travel around the room.  There was so much in the moment science and understanding of the world as we talked about what was happening.  We did go on to make the papier mache balloon too! Child led learning at its best.