Indoor games

At the French grandparents house with all the cousins from the French side (that's 8 children in the house), but it's raining!

Any good ideas to keep 8 children between 2 and 12 busy in a small house would be most welcome, I'm half expecting Thing 1 and Thing 2 to run in through the front door right now!

http://youtu.be/koAoQeEuECI
(The Temples-Move With the Seasons)