Defenders of Wildlife explains that penguins are social birds that live together in groups. Penguins communicate through both visual and vocal methods. They do this more often during mating season and with regard to nesting territories. Although some penguins are known to go hunting for food by themselves, it is much more common to see them swimming and feeding in groups. During the penguins' breeding season, they form large groups known as rookeries. These rookeries usually include thousands of penguins living together.
According to Sea World Parks and Entertainment, penguins are often seen preening their feathers. This is a common behavior of penguins because their feathers have to be in near perfect condition to ensure insulation and waterproofing when swimming in icy waters. Penguins have a gland near the base of their tail that secretes a special oil. Using their bills, penguins distribute this oil throughout their feathers, and this helps with waterproofing. In the water, penguins preen their feathers by rubbing their flippers over their bodies while twisting in the water.
Every single penguin has its own distinct call, according to the Defenders of Wildlife. This makes it possible for penguins to find their chicks and mates even when living in large groups. Although penguins are often seen on land, most penguins spend up to 75 percent of their entire lives in water. This is primarily because penguins do all of their hunting in water.