In some brands of Judaism it is customary to perform the kapparot rite in preparation for Yom Kippur.
The rite consists of taking a chicken and gently passing it over one’s head three times while reciting an appropriate text from the Torah.
Usually a rooster is used for a man, and a hen is used for a woman. For a pregnant woman, kapparot is usually performed with three chickens—two hens and a rooster. One hen for herself, and the other hen and rooster for the unborn child (of undetermined gender).
If a chicken is unavailable, it is possible to substitute another kosher fowl (besides for doves and pigeons, as they were offered as sacrifices in the Holy Temple). Some use a kosher live fish; others perform the entire rite with money, and then giving the money—at least the value of a chicken—to charity.
After the ritual, the fowl is slaughtered in accordance with halachic procedure and its monetary worth given to the poor, or, as is more popular today, the chicken itself is donated to a charitable cause.