Interesting - I'm not familiar with the anatomy involved in spider's sense of orientation, but I suppose it makes sense that they would have a fallback if this

Interesting - I'm not familiar with the anatomy involved in spider's sense of orientation, but I suppose it makes sense that they would have a fallback if this system wasn't working properly (ie they have the spider equivalent of vertigo). Alternatively, when swinging around making webs perhaps gravity isn't the most reliable means of determining orientation.