All 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.