GROWING UP FROM BABY TO ADULT

Chapter 1: The Start of Life

How does life start? Is it the same for people and animals?
Some animals, like birds and alligators, start life inside an egg. But many animals carry their babies in their bodies.
For the first nine months before humans are born, they grow inside their mothers. Baby cats are inside their mothers for only two months. A female lion carries her baby for about four months. And an elephant is inside its mother for 22 months.
The mother is usually the most important parent. The baby is safe inside her. It takes food from her. The mother often looks after the baby after it is born, too.
But sometimes the father is more important. For example, the female seahorse puts as many as 1,500 eggs in the male seahorse's body. The father then carries the eggs for two to four weeks. The eggs get food from his body until they hatch. Now the baby seahorse can look after itself. Dad's job is finished!
The male sea catfish is important, too. After the female puts her eggs on the sea floor, the male takes them in his mouth. And they stay there for about two months. Then, the eggs hatch, and the baby fish swim out to start their lives.

Chapter 2: Babies

All babies need their parents to look after them. Or do they?
Most new baby sharks can swim and look for food. But great white shark babies start finding food for themselves before they are born. They hatch out of eggs inside the mother and get hungry. They eat other eggs, and sometimes they eat
their brothers and sisters!
Adult snakes don't look after their babies. Snakes look after themselves from day one. The African black mamba is one of the world's most dangerous snakes. A baby black mamba is as dangerous as an adult. It can catch and eat small animals as soon as it hatches.
A zebra baby can walk about 15 minutes after it's born. After one hour, it can run. This is very important. Lions love to eat baby zebras. But baby zebras can run and stay near their mother and the other adult zebras. Then they are safer.
Other animals can do very little when they are born. The kangaroo is born after only 35 days inside its mother. The baby is very small: two centimeters long.
That's smaller than your eye! It climbs into its mother's pouch to be safe, and it stays there for 7 to 10 months!
Baby birds can't fly, and their parents bring them food every day. When they grow, they start trying to fly. Sometimes the mother helps. She stands near the nest with some food. The small birds try to get the food, but they often fall to the ground. After many accidents, they learn to fly.
Many baby animals really need their parents. So what if their parents die? Many adult animals look after the babies of another animal of the same kind. But dogs sometimes look after other kinds of animals, like kittens, baby chickens, or even baby tigers.
And what about us? There are about 370,000 human babies born every day somewhere in the world. Babies can't walk, talk, or see very well. (Some people think babies are good swimmers, but this isn't right. If you put them in water, they move their arms and legs, but they aren't really swimming.) A human baby dies very quickly if its parents or other adults don't look after it.
In the first two years, babies learn many things. At 8 to 12 months, they usually say their first word. Between 9 and 18 months, they start walking. But they're not like zebras. They will need the help of adults for many years to come!

Chapter 3: Adolescence

Adolescence is a difficult time, but why?
Let's look at humans first. Between the ages of 10 and 17, girls usually grow about 23 centimeters and boys about 38 centimeters. Girls usually get heavier by about 17 kilograms and boys by about 24 kilograms.
Teenagers can grow very quickly in a short time. This is called a growth spurt.
In a growth spurt, a teenager can grow more than 12 centimeters in one year. In girls, these growth spurts start earlier than in boys. This is why girls of 12 are often taller than boys of the same age.
And what about inside their heads? Do teenagers think differently from adults?
One part of the brain is called the amygdala. This makes us feel angry, happy, or sad. Another part of the brain, called the cortex, helps us make good decisions.
In adolescents, the cortex is small, so they use the amygdala much more.
Teenagers often get angry or sad very quickly. They often don't make good decisions and do dangerous things. Between the ages of 16 and 19, more people die in accidents than at any other time.
Most animals start adolescence at a younger age than humans. Elephants start adolescence when they stop drinking their mother's milk, usually between 5 and 10 years old. Adolescence usually finishes when they are 17. During adolescence, a male elephant leaves its mother and goes with a group of other young males.
But a female elephant stays with her mother.
Male lions start to grow a lot of hair on their heads when they are about 18 months old. This is called a mane. If a lion has a very big mane, it shows that he is a very important lion.
Adolescence in cats starts at seven months and ends at 12 months. At this time, female cats start looking for male cats to have babies with. And male cats leave a strong smell in the places where they live. This tells other male cats to stay away!
Dog adolescence is from six months of age. At about the same time, puppies also grow new adult teeth. This makes them feel bad, and they often chew things. This can be a very bad time for you, too, if you have a dog. The second teeth are strong, and puppies chew everything!

Chapter 4: Becoming an Adult

It's time to grow up.
People stop growing at different times. So when does adolescence end and adulthood begin?
In most countries, you're an adult when you're 18 years old. But in some countries, adulthood starts earlier or later. In Cuba, for example, you're an adult at 16, but in Egypt, you don't become an adult in all ways until you're 21.
Why is this important? Because when you're an adult, you can do many things you couldn't do before. For example, you can vote, get married, or drive a car.
In many countries, when somebody becomes an adult, they have a party. But in some parts of the world, people do dangerous things.
On the small South Pacific island of Vanuatu, young men jump from a high place, 30 meters above the ground. They put a long, strong rope around their leg. It stops them from hitting the ground and dying. But it's still dangerous.
In Australia, adolescent Aboriginal boys have to live alone for as long as six months in the Australian outback. The young men have to find food and water.
It's very hot and dry in the outback and there are dangerous animals, like snakes. In the past, most Aboriginal boys did this, but not many do it now.
In one part of Ethiopia, before a young man can get married, he has to run on top of some cows and not fall down. This shows he is leaving childhood behind and starting life as an adult.
And what about girls? The Mentawai people live in Indonesia. When a young Mentawai girl becomes an adult, her teeth become very important. She wants to make them as sharp as possible. She knows that Mentawai men love sharp teeth.
In Mexico, when a girl is 15, she becomes a woman. There's a big party (a quinceanera, in Spanish). People give the girl lots of presents, and everybody has a lot of fun!
When some animals become adults, their bodies become very different. For example, an adult frog is very different from a tadpole - a baby frog. A tadpole is born in water. It's like a fish. The tadpole then grows legs and becomes a frog. The adult frog can then leave the water.
And what about butterflies? The mother butterfly puts her eggs on a plant. A caterpillar hatches from the egg and starts to eat the plant. Then, it makes a cocoon, something like a little house. Inside the cocoon, the caterpillar changes. After a few weeks an adult butterfly comes out.

Chapter 5: What Do You Think?

Are you too old or too young? When is the right age to do different things?
Before 1940 in England, many children aged 5 to 14 worked on farms and in factories. In Africa today, about 65 million children work. In Roman times, girls often got married and had children when they became adolescents. But now most people wait until they're much older before they have babies. But what is right? When are we old enough to do things?