The Batak believe that three categories of "begu" exist. The "bicara guru" are the "begu" of stillborn babies or of babies who have died before teething. It is possible to turn "bicara guru" into guardian spirits if misfortune has befallen the family of the child shortly after its death. With the help of a "guru sibaso", the "bicara guru" can be made the family's guardian spirit for which a shrine is provided and to which sacrifices are regularly made. Once a year the "bicara guru" is accorded a special feast, preceded by ritual hair washing.