Reproductive plasticity – the ability of individuals to modify their reproduction and the characteristics of their progeny according to environmental or social conditions – is a crucial factor in the demographics of animal populations, including man. Two scientists in the Laboratoire Écologie & Évolution (CNRS/Université Pierre et Marie Curie/École normale supérieure de Paris) have demonstrated the ability of the individual females, of a certain type of arthropod, to adapt their reproductive behavior from one laying to another.