When seeking a cure for illness many Africans consult doctors trained in Western medicine, but have access to practitioners of traditional medicine who are also religious specialists. These people are also consulted about non-medical problems such as the identification of thieves or the recovery of lost property.The ritual experts or diviners use a range of devices with which to consult the gods or ancestors. The Luba use sculpted figures called bankishi which are considered to be an empty vessel until they are charged with powerful substances by the ritual specialists. These materials are thought to have rare and special powers such as human bones (life force) and the hair of twins (symbols of fertility) which are either wrapped in cloth and inserted into a hole in the figures' head or stomach or into the cavities of the horns.Sometimes the bankishi figures have multiple heads which may signify increased powers of divination and the ability of the diviner to see in all directions simultaneously.