I saw a documentary about the life of penguins. Like many other living organisms, from the day they are born, they have to face the rules of survival - survival of the fittest. From the beginning, penguin babies have to fight with their siblings for their mother's food, and will die if they lose the fight. The parents don't have time to feel sorrow, because there is nothing more important than survival. It seems very sad to look at it that way, but really, it is just that cruel.