Penguins are very faithful animals and they usually have only one companion all their life. In the same way that men offer flowers to a woman who pleases them, male penguins make their “marriage proposal” by offering a pebble.
When a male is interested in a female, he goes in search of a stone to offer. But not just any rock: he looks for the “perfect pebble” by digging long piles of pebbles to find those who are the most beautiful and the smoothest. Males often compete for the prettiest selections. When a penguin has chosen his most beautiful pebble, he presents it to his future companion. If she approves, she puts the stone in her nest, and the two lovebirds will become mom and dad penguin.