It is said that the reason why birds don't fly is that their wings have degenerated because they have been locked in cages for too long, which means that birds will degenerate if they don't have the ability to fly. Have you heard the story of boiling frogs in warm water? Frogs will adapt to the adjustment of water temperature, and so will these birds. They think they may not need to fly in the future, and they will naturally lose their ability to fly if they are bound for too long.
When releasing fish, the reason why fish don't swim is actually some physical knowledge.
Simply put, it is the water temperature. Because the water temperature is different, the fish may not be able to accept the cold water temperature when they are released, so they will swim around in the water with acceptable water temperature instead of swimming farther away, where the water is colder.
In fact, these are all tricks played by Li, in order to be able to let himself live his 60th birthday. At that time, it was the time to sign the treaty of humiliating the country, so Cixi's birthday was said to be the measure after removing many things.