Diggers

Madeleine and Marcus dig a pond.  They learn through experience that water don't stick, which is hard going if you want to fill the hole with goldfish and a frog or newt (Madeleine, over my shoulder now :  "Oh, Dad, don't put how it failed please").  They fit it with garbage bags then backyard rocks - which is where I put my foot down - to find them later digging up stones from the front road.  I warn them that the cops might come since there could be erosion. They still just believe me but barely.