Animal welfare is the physical and psychological well-being of animals. It is measured by indicators including behavior, physiology, longevity, and reproduction. The term animal welfare can also mean human concern for animal welfare or a position in a debate on animal ethics and animal rights. This position is measured by attitudes to different types of animal uses. Systematic concern for animal welfare can be based on awareness that non-human animals are sentient and that consideration should be given to their well-being, especially when they are used by humans. These concerns can include how animals are killed for food, how they are used for scientific research, how they are kept as pets, and how human activities affect the survival of endangered species. An ancient object of concern in some civilizations, animal welfare began to take a larger place in Western public policy in 19th-century Britain.