We look at the animals that kill representatives of their own species. The story begins with chickens which barely after hatching from egg begin the struggle of life. As the animal grows the battle continues: food, power, possibility to copulate. Any of these fights may end in death. The circle is rotated back: male may kill their partners offspring to get mating. But not all the animals are violent. At the end of the program we visit communities which instead killing their own species rather live in perfect harmony, where males and females, adults and offspring, brothers and sisters work together.