The Lemuria is a festival which takes place in May on three non-consecutive days. Since even-numbered days are considered to be unlucky, the rituals are observed on 9, 11, and 13 of the month. It is a festival of the dead, and its purpose is to drive away the hostile spirits (lemures or larvae) of deceased members of the household who haunt the house at that particular time. (The most terrifying of these spirits are those who died young since they are likely to bear a grudge against the living.) By performing the ritual correctly, the paterfamilias can ransom the living members of the household and dispel the ghosts from the house.
Each householder must arise at midnight, wash his hands in pure water, and make the mano fico to ward off evil. Without looking back, he walks barefoot through the house and spits black beans out of his mouth. Nine times he repeats the formula: "With these I redeem me and mine." He washes his hands again and clangs two bronze vessels together. Ghosts don't like the metallic sound. Finally, he expels the spirits by repeating nine times: Manes exite paterni ("Ghosts of my fathers, be gone"). He then looks back, and all should be well. The ghosts will take the beans and leave the household members unharmed.