He has to recharge his social battery.
He doesn’t like the jungle life he wants to go to the city 
A newly released orangutan went viral after building himself a tiny shelter on top of a post, and his former caretakers believe it reminded him of home.
The orangutan had spent years being rehabilitated at a wildlife sanctuary before finally being healthy enough to return to the jungle. But adjusting wasn’t easy.
Staff monitoring him noticed that other orangutans weren’t immediately accepting him, and he often wandered away from the group by himself. Soon, researchers discovered something unusual.
High above the ground, the orangutan had gathered branches, leaves and other materials around an old wooden post, creating a small makeshift shelter where he would sit alone. One of his former caretakers immediately recognized the behavior.
That looks man-made!
Back at the sanctuary, whenever the orangutan became overwhelmed or upset, he would climb into a small elevated treehouse and stay there until he felt comfortable coming back down. Nobody can know exactly what was going through his mind in the wild.
But to the people who raised him, his little shelter looked strangely familiar. He had finally returned to the jungle.
Maybe he just needed a small piece of home to make it feel like his own.
Monkeys doesn’t need to build shelters, they adapt to the nature and probably last longer than humans. Planet of the apes still possible 
Maybe he doesn’t like his new home and wants to go back to familiar surroundings. He looks really sad.
