A thing I've wondered, why do some spiders have a funky lil zigzag line in their web? There's this whole web, almost not visible, and then this very visible and chonky zigzag thing at one spot for some reason. Sorry if this wasn't specific enough, I've never been good at describing things. Hope you have a nice day though!
It's called a stabilimentum, and they come in lots of different shapes depending on the species of spider! "Zigzag spider" or "zipper spider" are common names for the yellow garden spider, Argiope aurantia, because of their stabilimenta, so most people are familiar with them, I think! The purpose is still debated, though. I've read a bunch of papers about it over the years, and I don't know what the leading theory is anymore, but past theories have included web stabilization (found to be unlikely), camouflaging the spider itself, which normally sits in the middle of the web and thus in the stabilimentum, making the web visible to animals like birds who might otherwise destroy it (seems counter-productive? why would you want a predator to know where you are?), and finally prey attraction, possibly by reflecting UV light, which insects are attracted to.
So...I don't have a good answer for you, and apparently neither do arachnologists :P
