Batak regard the loss of tendi as signifying a great danger for "body and soul". Tendi can be separated from their owners through inattentiveness, or as a result of black magic by a datu with evil intentions. In other words, the tendi is not tied to the body; it can also live for a time outside the body. The final loss of the tendi inevitably results in death. There are a variety of ideas about where exactly in the body the tendi dwells. It is present to a particularly high degree in certain parts of the body, especially the blood, the liver, the head and the heart. Sweat too is described as rich in tendi. It is believed that illnesses are connected with the absence of tendi, and the bringing back of the tendi is a main method of healing. The Karo, for instance, have gifts, called upah tendi (upah = wage, payment, gift), which they give to their tendi so that their tendi stay with them. These gifts may consist of a knife, a gong, a particular piece of clothing, a water buffalo or a small holy place. The gifts are carefully cared for in order to keep the tendi satisfied. Tendi love the sound of the surdam (a bamboo flute). If a tendi has abandoned the body of a patient, the playing of the surdam in the raleng tendi ritual can contribute to the tendi returning to the body of the sick person. It must be emphasized that only the datuk are in a position to interpret and influence people's tendi correctly. If their endeavors are unsuccessful, then clearly the tendi has chosen another destiny for itself. Death cult At death the tendi leaves the human body through the fontanelle and the "death-soul" (begu) is set free. It is thought that the tendi vanishes and after the death of any human being only the begu continues to exist. The Batak believe that the begu continue to live near their previous dwelling (in a village of the dead which is thought to be situated not far from the cemetery) and that they may contact their descendants. Bad dreams, particular misfortune and such like may be signs that the begu of an ancestor is not satisfied with the behavior of its descendants. Any individual can attempt to pacify an enraged begu by means of food and drink offerings and prayers.