I doubt there’s a spider enthusiast who is not familiar with enquiries about how to keep spiders out of the house. It hardly needs to be pointed out that spider-lovers are the last people who should be asked such a question – indeed, many would probably be interested in how to make spiders come into a house, if such a thing were possible. House spiders can be every bit as interesting as those outside, and a lot easier to observe. I shall not deny the excitement I experienced when I rediscovered the spitting spider, Scytodes thoracica in my house, nearly twenty years after I had last seen one. With such fascinating creatures willing to share one’s home, how anyone could want to have fewer spiders indoors is sometimes hard for me to appreciate. But to pass as a responsible member of society it is sometimes necessary to maintain a certain abstraction, and thus to entertain queries from those who don’t have the same enthusiasm for spiders.
Folk-lore about spiders suggests that one way to keep them from the house is to leave conkers around the place. Some swear by it, others refute it. Nobody really seems to be sure, although you can buy chestnut-based anti-spider spray on Amazon, so somebody thinks it works enough to shell out a fiver. But you don’t even need to do that – it seems that conkers, placed around a room, are supposed to repel spiders. The means whereby this is achieved are vague – some people refer nebulously to ‘a gas’ or ‘a smell’, but otherwise there’s not much to go on, as is perhaps understandable in the case of a folk remedy.
It’s an interesting suggestion, and one which I would like to know more about. My first thought is that the seasonal appearance of big, wandering spiders co-incides nicely with the appearance of conkers, and maybe somebody just put the two together in their mind. Furthermore, I have seen spiders quite happily disporting themselves on horse chestnut trees and amongst leaf litter containing conkers. But possibly conkers in a warm room emit a different smell to natural, living horse chestnuts or recently-fallen conkers.
Well, it turns out that somebody has checked, and found an answer. And it’s a bunch of schoolchildren from Cornwall. In 2010, the Royal Society of Chemistry for some reason thought they’d have a go at some biology. Perhaps they thought us zoologists were making a bit of a fist of it. Anyway, the project they decided to promote was to investigate whether or not spiders were indeed scared of conkers. The winners of the prize were Year 5 and 6 pupils at Roselyon School, a private school in Cornwall; who provided some evidence that suggested spiders were pretty much indifferent to conkers.
There’s even a video! Check it out.
A thoroughly enjoyable bit of school science. But does this prove the case? Well, up to a point. Clearly spiders, in these experiments, are not that bothered about conkers. But the experiments put the spiders in an unusual, fight-or-flight situation. Maybe a spider, seeking a new place to build a web, would weigh up its environment differently to a spider fleeing for its life. if so, perhaps the subtle smell of conkers could have an effect.
Frankly, my money’s on Roselyon School, I reckon it’s an old wives tale. But then why would I want to repel spiders?