I can't fly

This is a personal experience. Felt like writing about it.

I went to my relatives' place. They had purchased a set of love birds. They were originally six, but two of them died. They were swinging around in their cage and I felt that the cage was actually too small for them. I asked my uncle if he had ever let them free. He replied, "They can't fly, they have been bred in captivity. I let them free once. They could barely touch the ceiling and they came back."

I wonder if this is kinder- Not teaching them how to fly so that they don't know what they missed. 

This is not about some animal rights or anything like that. I just wonder that incapacitating somebody mentally so that they dont even think about going against the dominance is something more humane than actually capturing a free bird.