In this article I begin with a few current ideas on some physiological factors that influence mating choice in insects. Emphasis is placed on those proteins produced by the male reproductive accessory glands which increase female fecundity and reduce her receptivity to subsequent males. Strategies used by late-arriving males to favour their paternity are also mentioned. With a number of insect models as background, I then review what is currently known about several male factors in ticks (a capacitation factor, a male factor, an engorgement factor and a vitellogenesis stimulating factor) and suggest where we might focus our experimental activities in the future.