Yes, the whole predator/prey thing is unethical. I have been reading a book on the feelings and senses of plants. They, too, like most people, have limited sentience. Just how would you propose a lion acts "ethical" to its next meal?
Was it ethical for the lifeboat survivors to pick straws to see who would be killed for food so the others could live, and the next shortest straw had to kill him?
Isn't it ethical for a sensitive person, upon understanding life, to kill themselves, rather that the torment of knowing that to live, many other life forms have to die? Or should they rationalize some way for their mind to tolerate their own behavior to survive? Don't they lose ethics in that case? http://www.amazon.com/gp/product/037428 ... b_prodpg_2
What a Plant Knows: A Field Guide to the Senses
Humans are not all moral agents. Many have been raised or developed utter disregard for their own and others' lives, laws, and feelings. So many suicide bombers and shooters, and poachers ruining it for those who are moral. Some are just entirely immorally greedy or self-centered. Some are just mean and cruel, then when caught deny what they did. Many aren't much more than unintelligent herd animals going with the flow, incapable of deep learning and thinking ahead, and only taking on the morals of their herd or flock. Hence, the human gross overpopulation.
Those that are moral, intelligent, educated and ungreedy and living well with a low eco-footprint are a small minority. Most humans know good from bad and do good morally where society approves of law abiding and moral conduct. There are enough of the bad, however, to make it difficult for the good. Plus what many think of as good, is not, ecologically.