Male spiders use courtship gifts as shields to avoid being eaten by aggressive females.
Prior to mating, male nursery-web spiders (Pisaura mirabilis; male pictured on right, female on left) catch a prey item, wrap it in a silken package and present the 'nuptial gift' to the female. To find out why, Søren Toft and Maria Albo of Aarhus University in Denmark presented female spiders with males in the lab. They found that males bearing gifts were never cannibalized before mating, whereas 19% of females ate males without gifts. How hungry a female was did not significantly influence male survival rates.