"Love looks not with the eyes, but with the mind; And therefore is wing'd Cupid painted blind." So laments lovesick Helena in "A Midsummer-Night's Dream." Sorry to add to your woes, Helena, but not only is Cupid blind, he is more likely to glide on a trail of slime than fly on cherub wings. Cupid, it turns out, is rather like a snail.

Between ordinary land snails everywhere, in the back garden of your house and in your local park, one of the most extraordinary sex acts outside of Bangkok is taking place. Before copulation, snails circle each other for about half an hour, touching, nudging and biting. There is lip-to-lip as well as lip-to-genital contact. One of the snails then produces a bow-and-arrow apparatus from near the penis, and shoots a hard, sharp "love dart" into the body of the other. The partner replies with a dart of its own.

Snails are hermaphrodites, meaning they have male and female sexual functions in the same body. Unlike some fish species, in which individuals are males at one stage in their life and females at another, snails are both male and female at the same time. After the exchange of Cupid's arrows, each animal inserts its penis into the female genital tract of the partner, and each animal receives sperm, which it will digest or use to fertilize its eggs.