What’s scarier than a spider? Tens of thousands in one colony. Anelosimus eximius lives in South America, in webs that can cover entire trees. These massive clusters don’t just live together; they also hunt together, all moving in time to a bizarre stop-and-start rhythm.
When prey gets caught in a spider’s web, it creates vibrations in its struggle to break free. The spider feels these vibrations, and follows them to its next meal.
However, this isn’t as simple for Anelosimus eximius, because all the spiders walking across the web create their own vibrations. This can confuse them about where they’re actually supposed to go.
To stop this, the colony has a system. All at the same time, each spider will walk a short distance towards the prey. Then they stop and listen to where the prey is, before taking a few more steps. The timing even changes depending on the situation – the stronger the prey, the less time the spiders pause for.
Lachlan Writes Science 