Reproduction is a condition for the survival of living organisms. Animals demonstrate breeding behaviors that are specific to their species. Mammals often have specific breeding seasons.

Females of different mammal species have different estrous cycles. In some species, females go into heat only once a year, whereas in other species they can go into heat several times a year. Humans have menstrual cycles instead of estrous cycles.

The success of reproduction depends on a number of factors. The most important of these are the living conditions and the choice of partner, the latter of which is influenced by biological, mental and social factors.