In the primitive society, human beings lived together with birds and animals and therefore frequently attacked by wild beasts, beaten by snakes and stung by insects. Then, a legendary smart architect appeared. Taking a cue from tree-roosting birds, he made tree houses for human beings with branches and mud.

As living in the tree was very comfortable, the practice quickly caught on among the people. They no longer worried ab0ut being attacked by wild animals at night. Then, out of gratitude, people chose the architect as their chief and named him Youchao (literally meaning having houses).