Listen to the introduction of the videos on this page:
Video 1 is about an un-reached group called the Bara. You will get an impression of how they live. Cows are very important for them, but they do not eat them! Instead they offer their cows to the spirits of their deceased relatives—to keep them satisfied.
Video 2 is all about ancestor worship and the reburial of the dead. Many believe that the spirits of their deceased relatives are actively involved in their lives. They do their utmost to satisfy the spirits, by reburying the bodies for example.
A short impression of the Bara people on Madagascar
See how the Malagasy worship there ancestors. They rebury their ancestors to keep them satisfied.