The Nyangyatom, (also known as Bume) live south of Omo National Park. They occasionally migrate into the lower regions of the park when water or grazing is scarce. Numbering around 6-7000 in population, the Bumi are agro-pastoralists, relying on cattle herding and flood-retreat agriculture (consisting mainly of sorghum harvesting on the Omo and Kibish Rivers). The Bumi tend to indulge in honey and frequently smoke out beehives in the Park to get to the honey inside the nests. The Bumi are known to be great warriors and, quite frequently, active warmongers, they are often at war with the neighboring tribes including the Hamer, the Karo and the Surma. Small groups of Bumi living along the Omo are specialized crocodile hunters using harpoons from a dugout canoe. The elders of both sexes wear a lower lip plug, the men's being made from ivory and women's made from copper filigree.