Among the Idahan, women who know how to perform the required rituals may become spirit mediums ( babalian ) and do such things as curing and performing exorcisms of people and houses. Spirit mediums among the Kelabits, however, are old men who contact guardian spirits for advice about things such as rice planting. The Kelabits practice secondary burials. The death feast that accompanies the secondary burial is extremely expensive and takes place only every few years, usually on the occasion of the death of an aristocrat whose family can bear the expense for themselves (and for the poor, who take advantage of the occasion simultaneously to bury their own dead ritually). Kelabits are also known for their megalithic culture.