Humans are wired up to behave in the way they behave, and it is only the mind of man that misinterprets that behavior (via thought/speech). The struggle to stay alive (versus roll over and die), is hard wired into living things, lifeforms of all kinds, and Life is certainly not suicidal, regardless of all the human (only - for animals are certainly not doing this) doomsayers out there railing on about "the end of the world", and "armageddon" (which, by the way, has much more to do with their OWN inevitable end - death - than about the end of life on earth).
Also, humans are wired up to expand and stretch and push their nervous systems in a way that animals are not designed to do, because human nervous systems are "open-ended", rather than "closed-ended." This particular "striving", if you will, is precisely that which leads men to make up religions, philosophies and spiritual "teachings", and "believe in them." ALL of them have one thing in common, the expansion of the nervous system in the living (still alive) human, BEFORE inevitable death when contraction and dissolution take over. When this expansion actually does occur, it is more than just a rarity, because it NEVER occurs naturally, and certainly not "accidentally" without attention, intention, and forethought.
Humans ARE, for all intents and purposes, just animals - behaving just like ALL other so-called higher animals on earth - but with the added "blessing" (or "curse" depending upon your mileage pursuing these ideas) of "conscious thought". Humans can THINK ABOUT their situation here on earth, while animals without that capacity can not. This "thinking about" their particular situation is NOT what separates man from Life, for man can not become separated from Life, except at death. Men, "thinking about" their situation all the time, is designed into the mechanics of the nervous system - it is a necessary and crucial element for that expansion mentioned above - and it reflects upon its thoughts and actions, primarily to adjust that activity for future benefit if deemed necessary.