An animal sanctuary is a facility where animals are brought to live an be protected for the rest of their lives. Unlike animal shelters, sanctuaries do not seek to place animals with individuals or groups, instead maintaining each animal until his or her natural death. In some cases, an establishment may have characteristics of both a sanctuary and a shelter; for instance, some animals may be in residence temporarily until a good home is found and others may be permanent residents. The mission of sanctuaries is generally to be a safe haven, where the animals receive the best care that is possible for the sanctuary's means. Animals are not bought, sold, or traded, nor are they used for animal testing. The resident animals are given the opportunity to behave as naturally as possible in a protective environment.