Animals are used for many different services: companionship, guard dogs, therapy animals, truffle-hunting pigs, polo ponies, and so on. People harvest all sorts of animal products from wool and leather to glue and even heart valves. People also use them for testing products. In 1933, more than a dozen women went blind after using Lash Lure mascara (National Academy Press, 2004). The compounds in this product literally burned their eyes and resulted in blindness and even death in one case. This led to the use of animals for safety testing of cosmetics. Today, animal testing for safety and efficacy of drugs, sweeteners, food additives, and medical treatments is commonplace. These uses are controversial, however, not only because the animals may suffer during the process and are often euthanized at the end of a test, but because even closely related mammals do not respond to drugs or toxins the same way humans do much of the time.