Interesting question? I once asked myself this question. Until now, I haven't had an answer for it.

Unless wild animals are endangered by threaten of being hunted too much or becoming extinct, there is no logical reason that we should keep wild animal in zoo.

It depends on situation. I know that what I am saying is not practical when things happen, but I still say so. If for some reason, a woman tried to attack you with bare hand or kick you, just let it go. We don't need to defense in such cases. I agree with HighFalutin that only defense when really necessarily such as when she tries to stab you or beat you with a baseball bat,...