Additionally, animals are physically and mentally healthier in the wild than in zoos. They are able to have more exercise as they can run around and hunt in larger land spaces in the wilderness. Zoos do not have such large spaces. Caged animals do not know what it is to naturally hunt their food or to explore their environment and to select a mate. This I am sure can be mentally depressing for animals. Also not being able to climb, hunt and run will make the animals obese. In the wild animals are not able to eat their natural foods instead of artificial foods given in some zoos. And these unnatural foods will make the animals sick.