Animals, whether they are big or small, are essential to our ecosystem. Each animal plays an important role somewhere on the food chain. If an animal at the top of the food chain dies, then ones that would normally be killed off by that animal would now be at the top of the chain and would become much more plentiful. The plant or animal right under them on the food chain would dwindle until the animals that are now on top of the food chain had run out of or low on resources until they begin to fight over and kill one another for the remaining resources. This would continue down the food chain killing off more and more species of animals, insects, and plants until everything became extinct. Without animals on the earth, if there were any plants left, there would be nothing breathing out carbon dioxide for them to survive. So eventually everything on earth would die along with the animals and earth would become desolate.