Smell is one of the first developed senses in existence, as well as one of the most important. Out of the subphylum Vertebrata, the class Mammalia has the greatest olfactory perception and the most specialized nose. As in some other vertebrates, the sense of smell in mammals is distinct, but at the same time unlimited in its ability to distinguish odors. The first to notice the importance of scent glands in mammals were perfumers. These various glands produced the odors of musk, civet, castor and ambergris. Musk is taken from the preputial glands of the musk deer, civet from the anal glands of the civet, castor oil from the castor gland of the beaver, and ambergris from the intestine of the sperm whale (Macdonald and Brown 1985). Although the olfactory lobes are not as large as in many lower vertebrates, as has already been stated, in general the olfactory organs and structure are well developed in mammals. The level of development is related to the habits of the animal. This means that animals that rely more on smell in their behavior have greater sensory capabilities. Starting from this idea, the uses of smell in mammals are multiple. One of these uses, which includes many different behaviors, is social functioning. Odors can be used to convey messages within a population and these can be conditioned by experience (Jameson 1921). When meeting strangers of the same species, there are 3 basic models of olfactory investigation. These naso-anal, naso-genital, and naso-nasal contact points are where investigations are most often performed (Macdonald and Brown 1985). For example, when prairie dogs fight or are irritated, their anal glans emits a strong musky odor that other... middle of paper... is due to the fact that males and females of the same species mate together. to smell (Young 1975). In some mammals, males can smell a female from afar, and will travel many miles just to mate with her. In this way the male is attracted to the female, which is especially true for solitary mammals that spend most of their lives alone. Mammals also use smell to recognize the sex of another individual (Macdonald and Brown 1985). This is why we generally don't see males attempting to mate with other males, or vice versa. Once again, conferring with the second of Doty's reproductive olfactory categories, males emit olfactory information that increases the aggressive tendencies of rival males from the same territory to demonstrate dominance. The exact opposite was found in females. They emit information that discourages aggressive tendencies (Jameson 1921).