The yanamamo live in rain forests in northern Brazil and southern Venezuela
They tend to be a very violent group of individuals. they speak only in the form of yelling.
They even form groups to raid other tribes for their belongings!
Napoleon Chagnon went to live with the Yanomamo for 19 months to learn how they live. his first meeting did not go as he hoped, he was greeted with arrows pointing to his face and angry yelling in a laungage he did not understand.
he learned that the yanamamo lived in such a way that there was no privacy.
they even used a strange green powder to get into a strange state of mind