Quote by Arthur Schopenhauer

“This universal conflict is to be seen most clearly in the animal kingdom. Animals have the vegetable kingdom for their nourishment, and within the animal kingdom again every animal is the prey and food of some other. This means that the matter in which an animal’s Idea manifests itself must stand aside for the manifestation of another Idea, since every animal can maintain its own existence only by the incessant elimination of another’s. Thus the will-to-live generally feasts on itself, and is in different forms its own nourishment, till finally the human race, because it subdues all the others, regards nature as manufactured for its own use. Yet, as will be seen in the fourth book, this same human race reveals in itself with terrible clearness that conflict, that variance of the will with itself, and we get homo homini lupus.71 However, we shall again recognize the same contest, the same subjugation, just as well at the low grades of the will’s objectivity. Many insects (especially the ichneumon flies) lay their eggs on the skin, and even in the body, of the larvae of other insects, whose slow destruction is the first task of the newly hatched brood. The young hydra, growing out of the old one as a branch, and later separating itself therefrom, fights while it is still firmly attached to the old one for the prey that offers itself, so that the one tears it out of the mouth of the other. But the most glaring example of this kind is afforded by the bulldog-ant of Australia, for when it is cut in two, a battle begins between the head and the tail. The head attacks the tail with its teeth, and the tail defends itself bravely by stinging the head. The contest usually lasts for half an hour, until they die or are dragged away by other ants. This takes place every time.”

Quote by Arthur Schopenhauer