Making mud soup!

I'm not sure what age little boys grow out of making mud pies (or in this case soup) but I cant see it being anytime soon with my two.  A while back I replaced my saucepan set and the old ones made their way out into the garden to make a very rudimentary mud kitchen. Armed with a big bucket of water and a trowel, William and Sam can entertain themselves for hours out here now!