There are multiple ways dogs determine if the other animal belongs to their own species. For example, smell is a primary means of detecting relatedness and can help dogs differentiate between friends and foes. Sight is also an important cue for Dogs, and they use it to identify individuals, predators, prey and Familiar objects. In addition, hearing allows animals to detect movement and changes in noise levels within their environment. Lastly, cognitive processes such as categorization are often used by carnivores to identify food items from potential enemies or mates.