Penguins have very stiff wings that are sometimes called flippers. Like other flightless birds, penguins can’t use their wings to fly. But they can use them to swim.

Other parts of a penguin’s body are made for swimming, too. In fact, even the shape of a penguin helps it swim. A penguin’s body is shaped like a torpedo. With a body shaped like that, a penguin can easily cut through the water. A penguin also has strong, webbed feet and a stubby tail. It uses its feet and tail as a rudder to steer through the water.

As swimmers, penguins are strong and fast. They usually swim at about 8 miles (13 kilometers) per hour. At this speed, they can travel great distances. In short bursts, they can reach three times that speed.

Penguins flap their wings, or flippers, to dive deep. Most other diving birds use their feet to push themselves through water. Birds that dive using their feet don’t usually go as deep as penguins do using their flippers.

An emperor penguin can dive deeper than any other bird. It can go down as deep as 1,750 feet (530 meters). That’s deeper than the height of the tallest building in the world. When diving, an emperor penguin can hold its breath for nearly 20 minutes.

This superb diver is also the largest of all penguin species. An adult emperor can be just over 4 feet (1.2 meters) tall and weigh around 85 pounds (38 kilograms).

Penguins spend some of their time on land or on huge slabs of ice. But when they need to eat, they must return to the water. Most kinds of penguins, like Adelie (AD uh lee) penguins, return to the water in groups. That’s because an enemy, such as a leopard seal, may be hiding below the water’s surface. A group has more eyes to look out for an oncoming predator. And a nearby predator may have a hard time choosing which penguin to chase. A lone penguin is a much easier target.

Penguins have other enemies in the water to worry about besides leopard seals. Sea lions, sharks, and killer whales all prey on penguins.

On land, adult penguins are usually safe. But chicks that are weak, sickly, or left alone are always at risk of being attacked. Large birds of prey, gulls, and giant petrels eat penguin chicks if given the chance.

No, they cannot. Penguins don’t have gills for breathing underwater as fish do. Instead, penguins have lungs—just as people do. That means that they must come to the surface to breathe air.

When penguins need to breathe, they often leap clear out of the water. If they are traveling long distances, they might leap up about once a minute. But if they are fleeing from an enemy such as a leopard seal, some penguins leap clear out of the water every few feet. Besides allowing them to breathe, leaping helps penguins keep away from their enemies down below.

Being able to leap also comes in handy when a penguin needs to get onto ice or land. Most penguins can’t pull themselves out of the water onto an icy ledge or a rocky shore with just their flippers. So they leap instead.

Penguins have a few ways of moving about on land. One way is walking—or waddling! Penguins have bodies that are ideal for swimming, but not for walking. Penguins have tall bodies and short legs. This odd combination makes them rock from side to side when they walk. Penguins usually waddle slowly. But when penguins are in a hurry, they can waddle for short distances as fast as a running human.

Some penguins, such as rockhoppers, are good climbers, too. Often, the slopes they climb are icy and steep. But penguins can get a good grip because they have hooked toes. Sometimes penguins even use their bills to get better holds on the rock or ice.

Tobogganing, or sledding, is another way that some penguins move about on land. The emperor penguins you see here are tobogganing over ice and snow on their bellies. They “row” with their flippers and push with their feet.

On top of their skin, penguins have thick coats of feathers. Penguin feathers are good at trapping heat. They are the main reason some penguins can live in such cold places. The feathers are also waterproof. They keep penguins dry underneath, even while the birds are swimming.

If penguins don’t keep their feathers in very good shape, they don’t stay waterproof. So penguins spend several hours a day preening, or caring for their feathers. Penguins use their beaks, flippers, and feet to preen. For extra protection in the water, penguins spread oil on their feathers. The oil comes from a special gland near their tail feathers.

Penguins that live in cold regions have an extra layer of fat, called blubber. The extra layer of fat acts like a blanket to help keep the birds warm when the temperature drops. Penguins also use fat to store energy. That comes in handy when they go long periods without food.

Penguins shed their feathers because they become worn and damaged. When penguins shed their old feathers and grow new ones, it is called molting. Penguins molt once a year.

Penguins always molt on land or on ice. Until they grow new waterproof coats, they can’t go back into the water. And the water is where they need to go to find food.

Sometimes penguins might have to go for more than a month without food while they molt. To prepare, penguins eat as much as they can during the weeks leading up to the molt. Eating so much helps them add fat to their bodies. The penguins live off the fat while they grow new feathers.