In article <3c6ski$5cf at due.unit.no>, aka at nvg.unit.no (Anne Karin Amundgaard) writes: >I have also heard a story about girls living close together. After a >while they will get their period simultaneously! If humans have got >sex-pheromone receptors, I don't know, but this story make it seem very >possible. This is true. Does anyone know why this happens? Cybel