What is the meaning and form of "telling stories by eating drums"?

According to Miao legend, ancient floods flooded everything, and brother and sister survived by hiding in wooden drums, so brother and sister got married and human beings multiplied. Later generations worshipped their ancestors in the form of killing cows and offering drums, praying for the prosperity of the thatched cottage, wishing good weather and abundant crops in order to "eat drums and hide them." At that time, we will dance with wooden drums, bronze drums, Lusheng dances and sing solemn drum songs.