Million years ago, before humans start to evolve, we spread around the world to produce our posterity. To do that, food is indispensable, so our ancestors killed inestimable amount of other animals. It is understandable for such killing because it is necessary for living. Nowadays, humans are invading wild word not only for food, but also for entertainment and laboratory experiments. Invading animal world, in this case, it just means that we are interrupting wild lives. The evidences are zoo, experimental animal, circus, etc. we claimed to keep common or animals that are in danger, but in reality we are making money off of them, such as zoo.
In the zoo, we can see most of animals live in the small shelter with limited space to move around. Other larger animals such as elephants, polar bear, bears, and etc, they live together in a small area. The zoo provides food, shelter, cleaning, and other individuals that are in the same specie. This may seem to be nice with such a positive protection, but the negative side is that it shuts off their freedom. Their instincts of hunting and tracing in the wild land are fading away.
Out of many human activities, experimental animals have the most miserable life because they get experimented with all kinds of drugs and operations. sometime we are not sure if a new kind of drug wether or not would cure certain disease, people would test on animals such as chimpanzee, mice, and sometime insects. we would sometime see these animals in movies and the their shelter might just be a little case and might not even get exposed under the sun, bad odors and diseases are common under the condition. Although some might succeed, some just lead to a tragedy.
Another miserable example would be circus. On the surface, we see the best corporation between animals and trainer, but in the interior, these animals don’t live very well. They are scheduled to train about 15 hours, smaller animals live in small cages and larger animals live in a bigger cage, and unlike humans, these animals do not get days off. it is most difficult for elephants to perform certain performance because their body size is not designed for that. And big cats such as tiger and lion, they are afraid of fire naturally, but unfortunately, they are trained to jump through the loop with burning fire. Depending on the economic level of the circus, animals get different treatments, some died or some get better.
If we humans did not to interrupt with nature, some species of animals would not extinct, or at least they would fade away naturally due to the selection of the fittest. Some humans are hunting precious animals such as pandas, whales, elephants, tigers etc. for money, fashion products, or collecting interests, these animals now become the victims. If we humans did not invade and tear apart their families, they could still live well and wouldn’t worry about their freedom. Our invasion had now expanded to land, ocean, and even the broad sky.