Once a year, large groups of penguins return to the land at the same time. They do this to mate and to lay their eggs. Most penguins make their nests in huge gatherings called colonies. A penguin colony may have thousands of members. In fact, a colony of Adelie or king penguins can have 200,000 pairs of penguins.

Penguins usually form colonies close to where they themselves were born. And it doesn’t matter how far away from “home” some penguins are when it’s nearly time to mate. Sometimes they return thousands of miles across the open sea to get there.

Usually, both male and female penguins work together to build a penguin nest. First, the mates must claim a good spot. In the crowded colonies, this is not easy. Predators are more likely to hunt for eggs and chicks on the edge of a colony. So the good spots are in the center of the nesting grounds.

To make their nests, most penguins dig small holes under large rocks or bushes. Penguins near the South Pole can’t dig their nests because the earth is frozen. So they build nests of pebbles on the ground. King and emperor penguins don’t build nests at all. They carry their eggs with them on their feet wherever they waddle!

Penguin eggs need time and warmth to hatch. Most female penguins lay two eggs. Penguin eggs take 30 days or longer to hatch. The females of larger species, such as king and emperor penguins, lay only one egg. It needs over 60 days to hatch.

Until they hatch, penguin eggs have to stay nearly as warm as an adult penguin’s body. Most penguins sit or lie on top of their eggs to keep them warm. This is called incubation (ihn kyuh BAY shuhn). A king or an emperor penguin incubates its lone egg on top of its feet. A special fold of skin covers the egg to keep it warm.

In most species of penguins, both parents take turns looking for food and incubating. But with emperor penguins, the males do all the incubating. Since penguins can’t eat while they incubate, male emperors go without food during this period. It may be 65 days before males can return to the sea and eat.

Baby penguins don’t look like their parents—they look more like puffballs! Fuzzy coats of feathers, called down, cover the chicks from their heads to their feet. As the chicks grow older, they lose their fluffy feathers. Over time, they grow adult feathers.

Parents must guard their chicks until they are strong enough to protect themselves. Penguin parents pass food they’ve partly digested to their chicks with their beaks. It’s easier for the chicks to swallow food “served” like this.

Some kinds of penguin chicks stay at their nests for just the first two months of their lives. Others stay near the nest up to a year. The parents don’t guard them the entire year, but they do feed them. When young penguins are old enough, they leave the colony and learn to feed themselves at sea. Most return to land only to molt and to nest.

Yes! Penguins in a colony can make a lot of noise when they call to one another. Calling is important because parents and chicks can recognize each other by their voices. Without their calls, penguin families could easily lose track of each other in such crowded places.

Nearly every bird species has its own special calls, and so does each kind of penguin. Some penguin calls sound like the cackle of a hen. Some boom like a trumpet. Others even have a harsh cry that sounds like the braying of a donkey!

Penguins communicate in other ways, too. They may wave their heads and flippers. Sometimes they bow. When penguins fight for nesting spots, they may try to stare down one another. They also point at each other with their beaks. If one penguin just isn’t getting the message, another penguin may even charge.

Penguins make up the family Spheniscidae. The little blue penguin is Eudyptula minor; the emperor, Aptenodytes forsteri; the jackass, Spheniscus demersus; the rockhopper, Eudyptes crestatus (or E. chrysocome); the Adélie, Pygoscelis adeliae; the Galápagos, S. mendiculus.