They waddle;)
in the ground
outside in the ground they cluster together
Penguins do that, to protect the young from the cold ground.
Penguins jump to get from water onto land or ice floes, to escape predators, or to communicate with other penguins. They use their strong flippers to propel themselves out of the water and onto solid ground.
September
Penguins nest in groups called rookeries. Some of these rookeries can have over a million birds! A group of penguins on land is called a waddle. A group of penguins in the water is called a raft. Sometimes the penguin chicks in a colony stay together in a large group called a creche.
It comes from the ground in antarctica from seals or penguins that die.
Here are a few examples of syllogistic arguments: All humans are mortal. Socrates is a human. Therefore, Socrates is mortal. All birds have wings. Penguins are birds. Therefore, penguins have wings. If it is raining, then the ground is wet. It is raining. Therefore, the ground is wet.
Your query assumes that penguins are interested in controlling or maintaining land. Penguins are sea birds and visit Antarctica's beaches to breed. They make their homes in the sea, where they are supported by the aquatic food chain. However, during breeding season, some penguins are territorial about their nest areas. There are no indicators that the beaches of Antarctica are shrinking, so that any and all penguins that want/ need to breed there can be accommodated.
Penguins
There are no plant materials for nests there. Penguins have adapted to living and breeding in very harsh climates.
Unfortunately Penguins are one of the only animal or for that matter living things that do not reproduce. Of course if this statement is true it arises the question "How then are penguins still present if incapable of reproducing?" and a valid question it would be. However the population of penguins maintains its level of existence by other means than reproduction. For example immortality and penguin eggs growing from the ground much like the common potato.