A Singing-bird was confined in a cage which hung outside a window, and had a way of singing at night when all other birds were asleep. One night a Bat came and clung to the bars of the cage, and asked the Bird why she was silent by day and sang only at night. "I have a very good reason for doing so," said the Bird: "it was once when I was singing in the daytime that a fowler was attracted by my voice, and set his nets for me and caught me. Since then I have never sung except by night." But the Bat replied, "It is no use your doing that now when you are a prisoner: if only you had done so before you were caught, you might still have been free."
Precautions are useless after the event.