I must refrain from asking, are you stupid?
however, obviously, I have failed.
Every single living thing in nature, excluding humans, has a purpose and a reason. and I say living thing, rather than living creature, because I include plants to that statement as well.
Carnivores devour the herbivores as a source of food as well as to prevent the plant-eaters from over-populating and over-eating all the plant life. Carnivores also prey mostly on the weak and the sick which helps keep the rest of the herd strong and healthy. Carnivores can only fell prey if they are strong and healthy. Thus, natural selection keeps all animals strong and healthy. The herbivores dine on the plants and their seeds as a source of food as well as to keep the plants from over-growing and crowding themselves, which would choke them and kill them all. The plants consume a diet of sunlight and nutrients from soil rich with nutrients from the manure and carcasses of animals. The waste of both carnivores and herbivores provides the fodder for plant-life. The plants also produce oxygen, while consuming carbon dioxide, whereas animals breathe in the oxygen and exhale carbon dioxide. Animals will also eat the fruit of trees, which was created by the tree full of indigestible seeds specifically for the purpose of being eaten, so that the animal may carry away the seeds and deposit them elsewhere in a neat little pile of perfect fertilizer. Each benefits the other.
These are only but a very few of the most obvious examples of how perfectly nature balances itself. Every single action that any living thing(excluding humans) commits is a step in working towards that perfect balance. The reason trees create such an abundance of seeds and that animals have such large litters of offspring is because not all will survive. The squirrels may eat so many nuts, but the trees have made enough to compensate, else they would not have survived. The yolk of an egg was created extremely nutrient-rich to be consumed by the chick and sustain it as it grows from a microscopic speck to a full-grown chick. The yolk is, ultimately, food. Why then should it seem so strange that other animals would seek those vital nutrients for themselves? Especially if the egg is not fertilized, then should all that go to waste? There is no life whatsoever in an unfertilized egg, only the food which would have been consumed by the chick had one been produced. Even if the egg is fertilized, some must still be consumed to prevent the birds from over-populating.
Nature is the easiest thing for me to understand, and I despise how difficult it is for humans to comprehend it.