has some great examples of experiments showing how Portia jump spiders can "count", decide on routes, etc.
When hunting another group of jumping spiders called Euryattus, Jackson reports, Portia employs a clever trick. Euryattus females build nests in curled-up dead leaves suspended in air by silk attached to rocks or vegetation. Courting males crawl down the silk suspension ropes, stand on top of the nest and shake it in a specific way. The signal draws the female out of the nest. Portia appears to take advantage of this system by mimicking the male's shake and luring the female into an ambush.
For Portia, finding the right strategy is especially important when pursuing spiders that also eat jumping spiders. To attack a web-building spider, for example, Portia deceives the spider into moving closer by plucking some of the silk strands of its web. If the target spider is relatively small, Portia plucks the web to mimic a trapped insect, prompting the spider to rush over thinking it's about to have a meal – only to become one instead. But if the resident spider is bigger and potentially more dangerous, Portia may instead create a gentle disturbance similar to a fruit fly contacting a single strand at the edge of the web that the spider will slowly wander over to inspect. As soon as the target is close enough, Portia pounces and strikes with venomous fangs.
If these strategies don't work on a particular web spider, another of Portia's tricks is to shake the whole web so it moves as if a gust of wind had hit it. This acts as a smokescreen for the vibration Portia makes as it crawls into the target spider's web. In laboratory experiments, Jackson found that Portia will try different plucking methods, speeds and patterns until it finds just the right combination to fool each individual web spider it hunts – essentially learning on the job.
made me think of Adrian Tchaikovsky's "Children of Time" as he uses Portia as the smart spiders...
