Predation is one of the most powerful selection pressures in nature. This selection force has created a range of antipredatory strategies that co-evolve with predator traits. One of the most celebrated examples of the power of natural selection is defencive mimicry. In defencive mimicry, less toxic or harmless species mimic toxic or otherwise unprofitable prey species. One of such example is venomous adders (Vipera sp.) and their less toxic mimics (Natrix sp. and Coronella sp.). Mimicry strategies have important influence on population dynamics of prey species and their predators. Thereby it is important to understand the importance of protective mimicry on survival and population structure of these species. Antipredatory strategies should be taken account in conservation planning of snakes. For example, selective collection (illegal trading) of adders may change the dynamics of mimicry systems and may have serious impacts on snake populations.