In his anger he had met the first advances of the express messengers with growls, and they had retaliated by teasing him. When he flung himself against the bars, quivering and frothing, they laughed at him and taunted him. They growled and barked like detestable dogs, mewed, and flapped their arms and crowed. It was all very silly, he knew; but therefore the more outrage to his dignity, and his anger waxed and waxed.
What theme does the excerpt convey?
Wild animals cannot be caged.
Displays of emotion are not productive.
It is right to treat captors with kindness.
Humor can relieve stress and tension.