Instructions: In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.
Input: Article: Watching some children trying to catch butterflies one hot August afternoon, I was reminded of an incident in my own childhood. When I was a boy of 12 in South Carolina, something happened to me that cured me forever of wanting to put any wild creature in a cage. We lived on the edge of a wood, and every evening at dusk the mockingbirds would come and rest in the tree and sing. There isn't a musical instrument made by man that can produce a more beautiful sound than the song of the mockingbird. I decided that I would catch a young bird and keep it in a cage and that way have my own private musician. I finally succeeded in catching one and put it in a cage. At first, in its fright at being captured, the bird fluttered about the cage, but eventually it settled down in its new home, I felt very pleased with myself and looked forward to some beautiful singing from my tiny musician. I had left the cage out on our back porch , and on the second day of the bird's captivity my new pet's mother flew to the cage with food in her mouth . The baby bird ate everything she brought to it. I was pleased to see this. Certainly the mother knew better than I how to feed her baby. The following morning when I went to see how my captive was doing, I discovered it on the floor of the cage, dead. I was shocked! What had happened? I had taken excellent care of my little bird, or so I thought. Arthur Wayne, the famous _ , happened to be visiting my father at the time and, hearing me crying over the death of my bird, explained what had occurred: "A mother mockingbird, finding her young in a cage, will sometimes bring it poison berries. She thinks it better for her young to die than to live in captivity." Never since then have I caught any living creature and put it in a cage. All living creatures have a right to live free.
Answer: he had just got a cage
Output:
The boy caught a mockingbird because _ .