In the old days, a bu (trumpet–shell) was sounded to summon villagers or warn of impending danger. One person from each clan, known as Bungu Mabaig, was given this responsibility. Bungu Mabaig communicated a variety of messages with shells of differing sizes, each making a unique sound. Bu (trumpet shells) are found on the grassy seabeds and reefs surrounding Badu and provide a valuable food source. To make a horn, a shell is first dried and then a hole fashioned into its tip. These days a bu (trumpet-shell) is only used to summon worshippers to certain church services.