S1, E4: Milly and Molly's teacher is sad when her pet budgie dies. The girls buy her a new one, but the fun-loving bird they choose goes quiet as soon as they leave the Petshop. They can't understand what's wrong with the little fellow, until finally Milly and Molly return to the shop. The girls discover they have unwittingly separated the budgie from his mate; reunited, the birds are happy again.