Orangutans share about 97% of their DNA with humans. That means if you compared a tiny instruction book inside an orangutan cell with one inside your cell, 97 out of every 100 pages would be the same. You can see it in their faces - their eyes, lips and expressions feel surprisingly familiar.
Orangutans spend almost their whole lives in the treetops. They have arms much longer than their legs, which they use to swing from branch to branch. A male's arms stretched out can measure over 2 metres tip to tip - longer than he is tall. Every night, they build a fresh nest of leaves and branches high up in a tree to sleep in.
Baby orangutans stay with their mother for around 7 years - longer than almost any other animal except humans. The mother teaches her baby which fruit is safe, how to use sticks as tools to fish out tasty insects, and even how to use a big leaf as an umbrella when it rains.
Orangutans are very clever. In the wild they have been seen using a wide leaf to drink rainwater from, a folded leaf as a whistle, and a stick to test how deep a stream is before crossing. Some have even worked out how to copy what zookeepers do - including pretending to mop the floor.