Every year, millions of animals undergo painful suffering or death as a result of scientific research into the effects of drugs, cosmetics and other chemical products. While most people think animal testing is necessary, others are upset by what they see as needless suffering. This essay will look at some of the positive and negative aspects of animal testing. Many medical treatments have been developed from experiments on animals. Since animal share many features with humans, scientists use animals to test the safety and effectiveness of newly developed drugs before testing on small groups of patients. Medical teams practice new operation techniques such as transplants on animals, too. Without animal testing, many new drugs would be extremely unsafe.