BEACHCOMBER 107 YEARS OLD AND STILL LEARNING FROM SNAKES...

BEFORE proceeding further, be warned that this week’s column contains violence and scenes of a sexual nature. On the plus side, it’s mostly about snakes and snails, so you have little to worry about unless you suffer from ophidiophobia or molluscophobia.

Thank you for ignoring the warning. I am sure you’ll be pleased you did so, because there is some fascinating speculation about human kissing at the end. But first, the snakes and snails.

There are around 80 known species of snakes dining on slugs and snails including one called Pareas iwasakii, interesting because of the way it has evolved into a more efficient snail-eater. For a snake, the problem with eating a snail is getting it out of its shell. The most efficient technique for this depends on the direction of the spiral of the snail’s shell.

Most snail shells spiral clockwise. The jaws of Pareas iwasakii have around 25 teeth on the right hand side but only 15 on the left; very useful in prising the snail out of a clockwise-spiralling shell – though terribly frustrating when encountering an anticlockwise snail. The majority of snails spiral clockwise however, justifying the curious dental asymmetry. In 2016, a team of researchers from Japan and Thailand experimented and found that when one such snake sees equal numbers of clockwise and anticlockwise snails, it stares at them for some time, and then is significantly more likely to attack a clockwise one. Such visual discrimination is essential for snails – as a clockwise snail cannot mate with an anti-clockwise one – but for snakes to do so on purely gastronomic grounds is remarkable. Recently I wrote about the direction of human head inclination when kissing, and research showing around 65 per cent of people incline their heads to the right for a passionate kiss. Then, reading about Pareas iwasakii snakes made me wonder how we select a compatible kissing partner.

If snakes can detect suitable snails just by looking at them, can humans do something similar with potential kissing partners? Can they tell, just by looking at them, if they kiss in the same direction? Is this the true meaning of love at first sight?

Further research is clearly needed, if only to reduce the incidence of nose-bumping between incompatible kissers.