A dog's sense of smell is much more acute than a human's, in part because of the difference in how they work. A dog's nose contains more olfactory receptors than a human's, giving it a more acute sense of smell (Tyson, 2012). A dog would be able to sense where another dog has been and could use that to follow the same course during agility. competition. Dogs are able to recognize different human odors and would therefore be likely to recognize their owner's odor rather than that of other people (Schoon, 1996). Studies have also shown that a dog is not only able to identify a person by their scent. , they are able to recognize scents from different areas of a person when mixed with other samples, for example, a dog could recognize a scent from the same person's hand or elbow when given a selection from different people (Schoon et al.1994). It was even found that in some cases, dogs were able to distinguish between human twins, even when the odor was almost identical (Kalmus, 1995). This shows the range of odors the dog can detect at the end of the course and should ignore it to focus on overcoming the odors.