Contents The task of spermatozoa is to transport its DNA‐load as efficiently and safely as possible from the male organism to the female. Before it reaches its destination, it has to pass almost through the entire female reproductive tract, a potentially hostile environment. During passage, it is confronted by a sophisticated system that provides sperm storage sides but also possibly facilitates selection. The present review attempts to summarize the current knowledge of sperm interactions during that journey. A better understanding of the highly complex processes taking place between insemination and fertilization will be necessary to improve the efficiency of conventional reproductive techniques as well as for enabling the development and establishment of new ones.