I'm not really up to date on my Alien lore, but they're not really animals, are they? I'm pretty sure they're bio-weapons.I have one huge issue with Alien Isolation: the computer knows where you are at all times so the Alien always has some idea of where you are. There is never a chance of the Alien wandering far enough away that it will be a non-issue... there will always be times where you are essentially sneaking around it, only for it to be forced to spawn right by you to invoke more challenge. More, it never learns to avoid you if you actually manage to hurt it... it keeps coming back, unlike pretty much every animal in existence. It completely ruined my immersion.