If the egg is actually fertilized—which remains to be seen—this pair of penguin dads could facilitate Berlin Zoo's first hatching since 2002 by September. Their group of six king penguins includes just one female, and she has a habit of abandoning her eggs. The species lays single eggs that must be kept warm for around 55 days, so parental negligence is not an option. In fact, successful hatchings require two devoted parents: They have to take turns guarding the egg and going out to find food. This full-time babysitting continues for around a month after the hatchling emerges, after which time parents can take advantage of colony-wide childcare while they go out hunting.