But today, animal species are disappearing faster. This is the sixth big extinction and now humans are the biggest danger to animals. Think about tigers again. People kill them because they are afraid of them. Some people kill them for their beautiful coats or for medicine. Other people kill them because they like hunting big animals. Or they kill all the smaller animals, and then the tigers cannot find any food. People cut down the trees, too, and take away their habitat. In all these ways, tigers are in danger from humans.