Aqua Ducks (UK)
Aqua Ducks is the eighteenth episode of the twenty-first season. It was written by Mark Zaslove.
Plot
While Bob and the team are building an aqueduct between Spring City and Fixham, some ducklings mistake Muck for their real mother. When their nest is endangered by the aqueduct, Muck tries to find a way to save the nest and ducklings and get the ducklings back to their real mother.