What makes spider silk feel so weird?

Thanks to Sara Goodacre for the answer!

James - Is there something about spider silk that is particularly unappealing to humans, or could it just be our general aversion to arachnids? Sara Goodacre is a professor of biology at the University of Nottingham where she runs the spider lab.

Sara - Well, the first thing to say really is that spiders themselves are a really super old group of animals. I mean really old, like 400 million years old before even insects, nevermind the dinosaurs which are far more recent. This means that all the silks that spiders have are also really ancient and there's been lots of time for them to evolve to be different from each other. So as people might know, some are sticky, some are thick fibres, and some are incredibly fine, some are even electrostatic. And all of this difference likely matters when it comes to brushing up against a human hand because there might be different reasons for the weird feeling that the human gets. But notwithstanding this variety amongst spiders, the silks are actually all so really different molecularly to any other proteins, really. Any other silks, for example, that are made by silkworms. The closest thing, but it's still not very close, is the glue that sticks a limpet to a rock.

James - So James, that special sort of stickiness is potentially part of the weirdness you're experiencing. You're touching something very special and unique in terms of the molecules themselves, but just because it is unique, does that mean the touch of spider's? Silk is necessarily disconcerting. So

Sara - I guess any physical sensation you get from touching whatever the spider silk is, whatever the cobweb is, is due to the silk touching hairs on our skin, which we then feel, and silk and cobwebs tend to be really hydrophobic, and that means they move away from water. So they sort of tend to react like a piece of very dried, fluffed up cotton wool. And that in itself might be a slightly weird feeling. Personally, I can say I don't find cobwebs or spiders weird, and that might be because I'm used to them or because I'm not frightened of spiders. They're really part of my day job as I run a spider lab. Or it could even be that I perceive the sensation differently. Perceptions and how we perceive the world around us, as we know, varies amongst people and it's probably a big factor when it comes to how we at anything feels and when it touches your skin.