After lots of activity this is a great game to quieten things down.
large open room
Choose a large open room and get all the children to lie down and pretend to be sleepy lions. If you are doing a particular theme you can get them to pretend to be fairies, pirates, dinosaurs or whatever fits your theme instead. Explain that whoever moves after the game begins will be out. During this time you can walk around the room, talking to them and trying to make them laugh. Each child who is out can help you try and make the others laugh. The last person left sleeping is the winner.