Orangutans spend most of their lives in trees forests in Sumatra and Borneo. They get their food from the trees, and they build nests in the branches to sleep in. Their long arms help them swing from tree to tree. They use their hands and feet to grab and hold tree branches and food. Orangutans are very smart. They sit under leafy branches for protection from rain and sun, and sometimes even put a very large leaf on their head like a rain hat!

Siamangs are arboreal inhabitants of the Malay Peninsula and Sumatran rain and monsoon forests. Their distinguishing feature is a large throat sac that they use to make socially important vocalizations. These primates are endangered due to illegal pet trade and habitat loss.