Today’s Wonder of the Day was inspired by Madison from Clarksville, OH. Madison Wonders, “Why do people have pets?” Thanks for WONDERing with us, Madison!

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?

For centuries, people have taught animals to be their friends, helpers, and food. This is called “domestication” and it happened more than 11,000 years ago. Some animals—like dogs, cats, pigs, horses, sheep, goats, chickens, and cows—have been able to build relationships with people.

Experts think that there are six things an animal needs to have to be domesticated:

  • They need to be able to find enough food. If an animal is too picky and only eats certain things, it might not be able to live with people very well.

  • They must mature fast. People don’t want to spend a lot of time feeding and taking care of an animal that takes ten years or more to grow up.

  • They need to be able to have young while living in a place like a house or a farm. If an animal needs a special area or special things to have babies, it might not make a good pet.

  • They 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 not good candidates to live around people.

  • They 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.

  • They need to know who is in charge. Most animals have a social structure and need a strong leader. Most domesticated animals, except for cats, are happy to accept a human in this role.

We usually pick animals to be our pets that we know and are good at living with people. Some animals, like lions, porcupines, crocodiles, and kangaroos, are not usually good pets because they might not be safe or happy living with people.

Sometimes people might have a pet that is not a common animal, like a fox or a deer. These are called “exotic pets” and they are wild animals that have been trained to live with people. Even though some people have these types of pets, it’s not a good idea in general because they are not animals that can easily live with people.

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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