Do you have a pet? If you're like millions of kids around the world, you probably have some kind of critter at home that you enjoy spending time with. For many kids, this might mean you have a dog or a cat. Others might have a fish, a turtle, a guinea pig, or even a lizard.

Unless you're a very unique individual, though, you probably don't have a giraffe, a bobcat, an alligator, a whale, or a polar bear as a pet. Why is that? Wouldn't it be fun to have some of those really cool animals you see at the zoo as a pet at home?

Scientists believe that human beings first began to train certain animals to be used as companions, workers, and food sources over 11,000 years ago. They call this process domestication. Only certain animals, including dogs, cats, pigs, horses, sheep, goats, chickens, and cows, have been successfully domesticated all over the world.

Experts believe that animals must meet six criteria in order to be domesticated successfully:

  • Domestic animals must be able to find sufficient food near human settlements. Picky eaters that require specialized food sources will not thrive as domesticated species.
  • Domestic animals must mature quickly. Because human beings have limited life spans, they will not want to waste a large amount of time feeding and caring for any animal that takes a decade or more to reach maturity.
  • Domestic animals must be able to reproduce in captivity. Animals that require particular territories or courtship rituals will rarely make good domesticated pets.
  • Domestic animals need to be gentle by nature. Cows and sheep are good examples of animals that are usually docile. Wolves and zebras, on the other hand, tend to be aggressive by nature and are thus not good candidates for domestication.
  • Domestic animals must not have strong flight tendencies. Deer, for example, tend to panic and flee when scared. As a result, deer do not generally make good pets. Sheep, on the other hand, can be scared easily, but they also have a flocking instinct which tends to keep them together in herds when nervous.
  • Domestic animals must conform to a social structure that recognizes a strong leader. With the exception of cats, most all domesticated animals are willing to recognize a human caretaker as their leader.

These factors explain, for the most part, why we humans tend to keep as pets the animals we're familiar with. They also explain why certain animals, such as lions, porcupines, crocodiles, and kangaroos, do not generally make good pets.

Of course, from time to time you may hear about someone with a very unique pet, such as a fox or a deer. These are examples of exotic pets, which are wild animals that have been tamed through careful nurturing. The existence of individual exotic pets, however, does not change the fact that these species are not good candidates for widespread domestication.

While exotic pets may seem like they would be fun to have, they tend to require much more care, which can be quite expensive. They can also be dangerous, since even tamed animals can retain some of their wild characteristics, leading to the potential for them to harm humans.

Although it might seem like it would be fun to have a polar bear as a pet, you probably wouldn't want to keep your house as cold as your pet polar bear would need it to be. You would also probably get tired of the smell of fish from feeding it so often. In the end, you're better off sticking with a dog or a cat!

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