Representatives of the genus Rattus are characterized by the lack of extreme forms of adaptive specialization, along with the obvious adaptive extension. Migration proved to be important for the expansion of the living space of rats. The ecological interaction between rats and humans occurred due to peculiarities of rats’ migration. Rats invaded the human ecological niche with the minimal degree of biological competition. One of the ways of interaction has become commensalism that presented rodents the opportunity to obtain additional sources of food and indirect protection from predators. The progress of human society expressed through the development of agriculture led to the creation of sedentary housing and stimulated the emergence of the new relationship called synanthropy. Using commensalism as a basis, rats have become synanthropic, taking advantage of surplus of food, as well as of the benefits of sedentary lifestyle. The mechanisms of transition of rats to the synanthropic way of life are based, on the predisposition of concrete populations to commensalism and the similarity of biological needs to the dependent species, rat and the determinant - man. The industrial revolution stimulated the growth of cities, where anthropogenic conditions have contributed to the transformation of rats from sinanthropic to sinurban species. The urban environment remains very difficult for the survival of most animals. The inevitable reduction of the human contact distance poses a danger to the existence of animals. The initiation of measures to destroy rats began with the awareness and appreciation of the damage caused by them. The application of multiple procedures for the destruction of rats by humans has led to the survival and reproduction of only those with exceptional behavioral abilities. Rats in urban populations adapt not only to the environment, but also to the system of population relations. Thus, due to synanthropy and to sinurbanism, rats have acquired unique combinations of biological and genetical characteristics manifested in those conditions and obtained a vast complex of physiological, ecological and behavioral peculiarities, which contributed to the formation of ecological plasticity, necessary for accommodation in anthropogenic zoocoenosis.