Mummy duck is trying to lead her ducklings from their nest in Bitz's castle to the lake, but it's a long way, so Bitz and Bob help guide them there safely. On arriving, they realise they need to find somewhere for the ducks to sleep at night. Mummy duck is hard to please and doesn't want to sleep under the trees or in Bob's robo-helmet. Time to build a duck house - on stilts, so that it looks just like Bitz's castle. Let's hope that will fit the bill!