The poison that you are referring to is most likely: Venom - A powerful poison that can paralyze or kill the victim.
When encountering wild animals, it is wisest to assume a defensive posture.
They bascially kill animals for money. Poaching and Bushmeat trading are some of the commercial purposes for killing of animals.
pheromones
There are many animals that exhibit a variety of defensive actions. Snakes for example will bite if cornered or surprised.
Under dangerous circumstances, all animals will self-destruct.
to protect themselves or to protect there family
It is exploitation of animals for commercial use. Production of animals for food, medicine and other purposes.
Animals use noises to communicate with each other. Some animals use noises as a defensive warning when threatened. One example is the opossum making a clicking sound to ward off predators.
YOUR MOM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! just kidding. really i dont know
No, some animals have painful deaths when they do that
To hunt animals on the farms, to keep the farm animals safe.
marking animals for research purposes