People love and need animals. Animals are cared for both in their homes and on farms. Many also enjoy watching animals in zoos, or through movies and television. Small children love to play with toy animals. However, humans also pose a significant threat to animals. They invade their habitats and cut down trees where animals make their homes. Rivers and seas are polluted, and large animals are killed for their skins or for medicinal purposes. Currently, approximately 7,000 animal species are endangered. What can we do to protect the world's animals—from ourselves?