Love Dart of Brown-lipped Snail - (Cepaea nemoralis). Like many molluscs, the Brown-lipped Snail is a hermaphrodite, the species not having separate sexes. During courtship, the amorous pair attempt to shoot each other with a love dart. Resembling spear heads, love darts are formed internally and stored in a dart sac before deployment. Research has shown that the dart contains mucus that promotes sperm preservation mechanisms in the recipient, so helping the mating success of the snail that shoots it. Cressbrook Dale, Peak District National Park, Derbyshire. April. Dart 6mm in length.