Other than scent, vision and hearing are two of the most important senses the player has access to, and both of these can manifest in various different ways.
Sight and reaction to it is something that varies between AI. Each animal has a certain degree of binocular and peripheral vision, in accordance to real life. Tyrannosaurus, for example, shows a wide binocular vision, while Thescelosaurus has a more peripheral vision. Audition is also incorporated into the AI, as animals can hear the player's footsteps, meaning they will react different to the player walking rather than running. Walking will make the player stealthier, while running will announce the player's presence. Big animals will have trouble in detecting footsteps of smaller animals, but smaller animals will easily detect footsteps from bigger beings. Dakotaraptor are able to crouch, by holding CTRL, which is a stealth mechanic that helps stalking prey without being as easily detected if not using crouch.
AI animals, as well as the player, can hide themselves in the environment. The player may hide itself in the foliage to block the sight of many animals, remaning hidden from predators or prey. AI animals may use the same technique to hide from the player and other AI.
The player's vision is from a third-person perspective, and so the player can roll its viewpoint, looking to the player from the sides, from the back or from the front, which will allow the player to see threats from various directions. Because the player's creature has a specific range of sight, the creature will often turn its head to accomodate the player's perspective. Sometimes, the player's creature can see things the player doesn't. The playable animal will often point its head to another animal that will indicate its presence. The player locks its sight to another creature, even if the player can't see it, like a Chamops hidden in the foliage. This is a useful alternative tool to locate nearby prey (in the case of Dakotaraptor), but the sight also locks itself to predators, carcasses and other offensive or inoffensive living animals, as well as edible plants (in the case of Triceratops). The player will walk and run according to the direction of the screen, moving forwards away from the camera by pressing W, moving to the left or to the right, by pressing A and D respectively, and moving towards the camera by pressing S. By keeping the mouse wheel pressed, while walking, the player will move in a locked direction while you are able to move your mouse around and see the surroundings. By pressing T, the player is also able to activate an auto-walk toggle that allows the player to walk in one defined direction without continuously pressing a key, and allows the player to see its surroundings while maintaining an automatic walking, and can be turned off by pressing T again.
Another alternative sight feature is the "target mode" or "aim mode", which is achieved by clicking RMB. The target mode displays a visual perspective, where the player sees through the animal's shoulder, and proceeds to aim to a target. It can be used to take down small animals like lizards and birds, snatching them with precision, or aim to hit larger animals, while hunting, in the case of Dakotaraptor, or charging, in the case of Triceratops. The target mode also activates some sort of slow motion, allowing the player to have faster reflexes when taking down creatures that are fast and nimble, like a Chamops, or evading an unexpected predator. It may be used as well to dodge obstacles with ease. The aim mode displays three tiny spots that can turn red when the player locks its target to a living animal, informing the player when to strike, or can turn green, when the player locks its target to food (i.e. dead animals or plants). By pressing R, you are able to move your camera with more flexibility, while still in aim mode. You get out of aim mode by clicking RMB again.
Animals also generate vocal sounds. You can press 'F' to open the call wheel, which gives you the option to select a threat display. When clicking in one of the call options, a mouse cursor will appear that allows you to direct the call to a specific target, usually another animal. A threat call can lead to an aggressive reaction, if the animal you're threatening is larger and/or stronger than you, or lead the threatened animal to leave and run away, if the animal is smaller and/or weaker than you. Some animals will completely ignore your threats however. For example, Pachycephalosaurus may tend to attack the player with more ease when you use the threat display and crocodylomorphs can react to the threat display, by standing still with their mouths wide open. Another call option is the mating call, which can be selected on a compatible mate or be broadcasted in the absence of one, in the hopes that a suitable mate may spawn in. In Triceratops, there are other call options available, including a social call and a warning call, plus an option to view your herdmates (if you have them), and a compass to know the direction of your herdmates. Social calls are targeted to other Triceratops in an attempt to keep social bonds stronger and let yourself be accepted by a new herd. Threat calls, in Triceratops, are only achieved at the start of the juvenile stage and can be directed at perceived threats, like predators, intruders and other dangerous animals, in attempts to scare them away and warn them about the danger that you can inflict in them. Warning calls are targeted to threats as well, but their purpose is to warn your herd of that threat. False threats and warning calls can be delivered, but those will affect your reputation alongside the herd, and at extreme levels, it may even lead you to be banished by the herd.
Other animals create sounds of their own too, to which the player can react. Chamops only sounds are their loud and tiny footsteps, that announce their presence nearby. Palaeosaniwa will hiss, like a snake, to warn the player of its poisonous bite. Crocodylomorphs will create threatening crocodile-like hisses, as the player approaches close enough that they attempt to bite. Thescelosaurus make bird-like whistles and screeches when getting hurt, but otherwise they are pretty silent, making them hard to spot just by hearing. Pachycephalosaurus make low typical herbivore noises, but they can make high pitched noises of pain. Triceratops make deep rumbles as adults, and small raucous screeches as youngsters. Ankylosaurus and Anatosaurus make very low deep herbivore noises, the latter of which makes elephantine and cetacean like sounds. Anatosaurus can also make bellowy rumbles, while pointing their head upwards, as a form of warning call. Denversaurus makes bison or bear-like deep breaths, when it gets hurt. Tyrannosaurus make few noise, which makes them incredibly stealthy, but can deliver a loud and deep growl if needed. Ornithomimids produce high pitched seabird-like or goose-like calls when threatened, but their threat display is a much more throat-derived version. Acheroraptor usually make many noises, as they produce raspy screeches that are very distinguishable and announce their presence. Pectinodon will create deep scary screeches or bellows that cover the nocturnal soundscape of Hell Creek. Dakotaraptor make different calls as they age, as hatchlings have a sort of songbird-like screech, but as they grow they gradually develop a deeper, bird of prey like sound. Didelphodon makes a noise resembling that of a bear cub, small dog or a tasmanian devil, when it gets hurt. Quetzalcoatlus apparently can also make vocalizations, represented by a very high pitched bird-of-prey-like screech. Champsosaurus makes a low reptilian growl when it attacks or is being hurt. Turtles, mosasaurs, fish and ornithurans don't make vocalizations.
Sometimes the background music in the game also reflects the player's status. If the player is close to a predator or a prey different compositions will play. Other compositions will play randomly during the gameplay, or according to the state of the player, if it is running, injured, feeding, hunting or healing, or according to many environmental states in the game, or even according to the player's location.