On morality
There is no objective morality, which is a concept by which humans try to rationalize the world and, mainly, to find a constant rule to follow and, therefore, acquire security, happiness, all of which amount to the idea of survival.
The ethical system incorporates a sizeable amount of components, some of which vary significantly depending on the period, geographical position, age etc. and, to some extent, are comprised by the so-called common sense, which can easily be discarded often as nonsense and laziness to adapt, if one would give enough thought to it and more or less cynical concentration. Needless to say, the terms good or bad are circumstantial most of the time.
However, things, it seems, get more rigid whenever it comes to those aspects that affect life and death, and so killing is forbidden in most cases, of course with minor exceptions. This is why we nourish the illusion that there is some objectivity in the moral code because our instinct represents the root of our being, the source of our desires, the incentive that moves us relentlessly even when following the voice of rationality and pure intellect. And usually, we cannot tolerate the universe without believing in something, be it fanatic religion or an atheistic philosophy.
But it is all just a game. The crocodile is evil in the eyes of his prey, whereas he is just succumbing to his urges. That's not to say that our kind must justify the actions which contradict severely the commonly accepted boundaries of behaviour, murder being the most preeminent example, but that doesn't imply that the instrument which helps us has an existence independent from our cognition. We do our best to be alive, whereas the universe is only interested in recreating itself over and over again in different manifestations, each of which has its own, predetermined instruments to cope with the unknown.