English Original
A singing bird was confined in a cage hanging outside a window. It had a habit of singing at night while all other birds slept. One night, a bat came and clung to the bars of the cage, asking the bird why it was silent by day and sang only at night.
"I have a very good reason," said the bird. "Once, when I was singing in the daytime, a fowler was attracted by my voice. He set his nets and caught me. Since then, I have never sung except at night."
But the bat replied, "It is no use doing that now that you are a prisoner. If only you had done so before you were caught, you might still be free."
Precautions are useless after the event.
中文翻译
一只鸣鸟被关在挂在窗外的笼子里。它有个习惯，总在其他鸟儿都睡着时在夜里歌唱。一天晚上，一只蝙蝠飞来，抓住笼子的栅栏，问这只鸟为什么白天沉默，只在夜晚歌唱。
“我这样做有充分的理由，”鸟儿说。“曾经有一次，我在白天歌唱时，一个捕鸟人被我的声音吸引。他设下网，捉住了我。从那以后，我就只在夜里歌唱了。”
但蝙蝠回答说：“你现在这样做已经没用了，因为你已是囚徒。要是你在被抓之前就这么做，或许你现在还是自由的。”
防范措施在事后是无用的。