The point of love

During the final stages of courtship, helicid land snails pierce each other with calcareous ‘love darts’. This bizarre sexual device has been claimed to be a nuptial gift or an indicator of the readiness of a ‘shooter’ to mate. However, these explanations are not supported by new work, which shows instead that mucus introduced with darts paralyses the female reproductive tract, allowing sperm to avoid female digestion and so make it in greater numbers to the sperm storage sacs. Love darts increasingly look like male instruments that are designed to manipulate females, although a role in mate choice cannot be excluded.