In the past, zoos were places where we saw single animals in small, empty cages. Today zoos are changing in design; animals have more space, and some live in groups. Many zoos try to put animals in an environment that is similar to where they live in the wild. Some people who believe in animal rights argue against having zoos, because they think it is wrong to put animals in l support the idea of having zoos, because they allow us to see wild animals that we cannot see otherwise, and they help endangered species from becoming extinct.