Inexplicable enjoyment

Just when you thought you had seen everything... a piece of footage on the BBC website makes you think again. This short video shows dolphins in North Wales clearly flicking jellyfish into the air.  These jellies (est 40cm+ diameter and weighing in excess of 10kg) are common in the area, don't sting and certainly don't compete with the dolphins for food, so why do it? My only explanation is for sheer pleasure.  Oh to be a dolphin....