why do animals become endangered or extinct?

Animals can become endangered or extinct for a number of reasons. Humans hunting them into extinction has been a common problem. There are also environmental factors. Severe climate changes can cause species to go extinct. Chemicals used to spray crops can cause populations to decrease. Some animals protect other animals. If we take away one species or introduce a new one into an area it can throw off the natural balance and cause some species to go extinct. Eco systems are very delicate. As the human population grows we are displacing more and more animals. With less space and resources to find food and water these animals die off.