The Penan staff of life is the wild sago, which grows in lower elevations and sporadically in the mountains. Animals are hunted as well, using spears and blowguns with poisoned darts, though firearms are becoming common. The game is primarily gibbons and macaques, though the wild pig is most desired. Fish are caught with hook and line, as well as poisoned with derris root. Food is shared. The Western Penan also make iron tools. The Penan trade with Kenyah people at the latter's longhouses three times annually, giving such things as hornbill feathers, wild latex, damar, and anteater scales. In return, they receive, at a disadvantageous rate, spearheads, knives, cookware, jewelry, matches, etc. Goods that they receive in trade are not shared. Land is not owned, but goods that the Penan trade with others are the property of the collectors. The Penan do not prevent other people from using the land that they themselves use.