Its moral is: lightness/movement/dexterity/boldness. It is widely used in brand trademarks.
Its source "Book of Rites Quli Shang": Parrots can talk without birds, orangutans can talk without beasts. "Lu Chunqiu's fame": the tree wants to be prosperous, and the bird wants to return. Chu Ce IV Warring States Policy: Lei Geng and Wang Wei look up at the birds under the Beijing platform. Lei Geng asked Wang Wei to say, "I bowed to the king, but I got off the bird. Once, geese flew from the east, and Lei Geng sent them down for nothing. Ode to the White Horse in Yan Yanzhi during the Song Dynasty: The Balance of Birds. Luo Guanzhong's Romance of the Three Kingdoms in the Ming Dynasty: The antlers in the burial village are ten times as heavy. Although birds can't enter, why worry about thieves and soldiers?