Have you ever given a baby a bottle? It's an important job -- and it needs to be done right. Erin learned the art of feeding an infant when she got a summer job babysitting for a 6-month-old boy.

Erin soon found out that when babies drink their bottles, they like to be cuddled. She also found out that it's important to make sure the babies burp after they drink.

"Just pat his back gently, or bounce him up and down a little bit," the baby's mom explained.

Erin tried it, holding the little boy on her shoulder and jiggling him up and down as she stroked his back.

"Urp!" he said. Both Erin and the baby's mom laughed. "That was a good one," the baby's mom said.

Erin thought it was pretty funny that the baby was being praised for burping. When Erin burps, her mom says, "Say 'excuse me,' Erin, please."

A burp isn't really all that rude -- although the sound does offend some people. It's just your body's way of getting rid of swallowed air. When you gobble a container of french fries, you swallow air along with the food. Before long, you may feel like a burp is on its way.

You have two separate pipes in your throat. Your windpipe carries air into your lungs when you breathe. Your esophagus takes food to your stomach. When you're eating, the opening to your windpipe closes automatically to keep food or drink from going down. It's rare for something to go down the wrong way. But it can happen. Almost everyone has had the experience -- and found out that the body has a natural response to get rid of the invading stuff.

When something goes down your windpipe, you automatically cough, and your windpipe makes a choking action that pushes the food back up again. Your esophagus stays open when you eat, of course. Otherwise, your food wouldn't be able to get to your stomach. As the food goes down, air goes down too. The extra air in your stomach can give you an unpleasant sense of fullness -- but burping relieves that feeling.

When you drink carbonated soft drinks, you swallow lots of the gas bubbles that give the drink its fizz. Those bubbles can also lead to burps. Some foods that have a lot of air mixed into them to make them light -- like whipped cream -- can also make you burp. Talking a lot as you eat can lead to swallowing extra air and to extra burping.

Many adults think that burping is rude, so you might try to keep the gobbling, chewing with your mouth full and soda guzzling under control.

Babies need to be burped because they swallow a lot of air with the liquid they suck in. If the air travels down into the stomach, instead of popping back out the mouth, it can cause the baby pain. This happens because the air expands, or grows larger, as it warms up inside the baby's stomach. It pushes the walls of the stomach outward -- and that hurts!

There's even a medical name for this condition; it's called aerophagia. "Aero" means air. "Phagia" means eating. The name shows that the baby got its stomachache from eating air. If you have ever been around a baby with a stomachache, you know they can yell their heads off.

Helping a baby get rid of the extra air by patting it lightly on the back can go a long way toward preventing that problem. No wonder mothers praise babies who burp.

Babies, like kids and adults, sometimes get the hiccups, too. Like burps, the noises can happen at embarrassing moments.

Hiccuping happens when your normal breathing pattern gets interrupted. Experts aren't sure why this happens.

The diaphragm -- a powerful muscle that helps you breathe -- gets out of rhythm with the rest of your breathing muscles. It sends an unusual gust of air rushing into the lungs. At the same time, your brain tells your tongue and the upper part of your throat to clamp down to stop the rush of air. As the diaphragm pushes and the tongue clamps, the air jets across your vocal cords, and you make that weird sound we call a hiccup.

There are many, many different "cures" that people try, but the best cure for the hic-hic-hic-hic sound appears to be time. You just have to wait for them to go away! And they do.Tips for Parents

Most of the time, parents can depend on the body's efficient choking-coughing reflex to protect youngsters when something they're eating "goes down the wrong way." There are also things you can do to make sure accidents don't happen. These recommendations are adapted from "Your Growing Child" by Penelope Leach (Knopf; $14.95). Don't let kids "throw" food into their mouths even for a joke or game, and don't let them pour nuts, chips or small candy from the package into their upturned mouths. Don't let kids suck on candy or cough drops in bed. In addition to being bad for the teeth, this practice is dangerous because kids may fall asleep and choke on what remains. It's best to not let children eat anything while they're lying down. Don't let kids eat while playing active games. A sudden push can lead to something going down the wrong way, especially if the youngsters are breathing hard. Don't let kids hold their noses while they're taking medicine. Trying to breathe through the mouth and swallow at the same time can lead to choking.

Catherine O'Neill is a free-lance children's writer based in Baltimore.