massacre
While ocelots are wild cats and can be dangerous due to their sharp claws and teeth, they typically do not pose a significant threat to humans. Attacks on people are extremely rare, as ocelots tend to avoid human contact. However, like any wild animal, they can defend themselves if threatened. Overall, the likelihood of an ocelot killing a human is very low.
Lions are used for killing people
A lot of people are killing them. People take their eggs for food so no birds will be born. The bird's predators are eating the and killing them.
Yes recently there was a law that you cant kill elephants for any reason unless it is killing people
Generally, shrews do not pose a threat to humans and most species are too small to break human skin with their bite. However, if cornered or threatened, they may try to defend themselves by biting. It is best to avoid handling shrews to prevent any potential bites.
Genocide
Murder, genocide.
People who cannot protect or defend themselves, from the age of newborn to age 14 most children will not be able to protect themselves from harm. Also old people who are fragile cannot protect themselves as someone who would be middle-aged.
by killing people.
Your question is not well phrased. The law allows someone to kill to defend themselves, they nevertheless still have to prove such a circumstance. Should a person be allowed to kill in self-defense? That is a personal choice.
Anybody could do what they wanted including taking things that do not belong to them and killing other people. People would have to defend themselves. There would be no "society".
to defend themselves
God tells them to defend themselves, and fight for what is right if needed. Therefore, they will not start a fight for no good reason, but they will kill if they must, to defend themselves, other innocent people, or the the freedom to do God's will. They are directed not to murder (see the sixth commandment) but the aforementioned situations are not premeditated, hateful murder.
Defendants.
they want to defend themselves
Generally, it is best to let people defend themselves. They might not care for the way you go about it.
Billions. Depends upon your definition of 'know how to defend themselves' is. Pretty much everyone is going to try to protect themselves if they are attacked. If you mean effectively defend themselves it would be a different story. And how many people have taken self defense courses or martial arts is another story all together.