Spiders can be remarkably intelligent. The Portia Jumping Spider is a spider that preys specifically and solely on other spiders. It's smart enough to analyze the web of other spiders, know which strands to snip to make the spider it's hunting be less mobile and easy to catch, smart enough to know how slow to go to not alert the spider, it knows how many to cut and not cut, it knows the spider is essentially blind ((Jumping spiders are among a few spiders with good eyesight)) and it knows which strings of the web to pluck to emulate a bug trapped in the web.

https://www.youtube.com/watch?v=DEjYYY9KjnU - If you can handle the cheesy sound effects ((I can)) this is a documentary-esq video of the portia vs a long jawed orb weaver.