Animals from the actual area definitely need to be added into gameplay. I agree on the spider thing, you couldn't make them obvious enough without making them huge, which is stupid. So while hiding in the dank dark corner of a barn and I suddenly start convulsing and die is going to piss me off. However, if going for realism, we need to add more than just predators as they would only be in the area if there was ample prey for them to survive off of (cue hunting animals for food addition). While in a post apocalyptic environment animals would likely begin to get more aggressive towards humans, unless the player is chasing, cornering, or threatening their den/home, most animals, even predators, aren't going to just run up and try to eat your throat. There are enough dangers in the game to have to worry about packs of wolves, boar, and bears just romping around eating anything that moves.