It probably never occurred to you to wonder what controls ejaculation in insects. A multinational group of investigators did, however, and their results lead to a chemical mystery.
The queen in social-insect species like bees, wasps, and ants usually obtains a lifetime supply of sperm from a single, brief mating period. Since these critters aren’t bound by conventional notions of monogamy, several males may deposit sperm. This ensures that the queen acquires a lifetime supply and is therefore prepared to meet her full reproductive potential.
The work of Den Boer et al. shows that the seminal fluid of competing males contains substances that damage the sperm of others (Science [19 March 2010], 1506–1509). Talk about male vanity!
The queen will have nothing to do with the contending males, though, since her interest is to preserve a large and diverse repertoire of viable sperm that will last through her life. Consequently, she counters by making another compound that thwarts the sperm-killing substances from the preening males.
I will wisely resist the temptation to draw any metaphors with human behavior. Nonetheless, I am curious as to the chemical identity of the spermicidal and anti-spermicidal entities that these busy insects produce. It isn’t even known whether they are small molecules or large macromolecules. My hunch would be the latter, since more specificity would be likely for such a complex system, but actual research yet to be done is much preferable to mere hunches.