From time to time, you hear of a bizarre scientific discovery in nature that shows how some insects can literally change their hosts' behaviour. This is done by injecting a special kind of parasite, which leads one to assume that the possibility of a zombie apocalypse is not impossible!
But let's not get ahead of ourselves just yet. Scientists recently observed a new parasitic behaviour between a specific type of wasp and spider. After the spider is injected with a parasite from this wasp, it relearns an ancestral behaviour. One that was otherwise erased from existence thanks to evolution.
The Anelosimus Eximius spider has a unique characteristic. They do not make webs solo, but rather as a group, and they never leave their home web either. Scientists have discovered a gene associated with exploring beyond the web and have found that it is suppressed in this breed of spider.
However, the Zatypota wasp lays its eggs on spiders so, when the larva hatch, they can feed on the spider's hemolymph. But, in doing so, the larva injects a special kind of parasite that modifies the type of web the spider builds, resembling that of a perfect cocoon for the larvae to grow in. Furthermore, this parasite also controls the spider to move away from its colony and build its cocoon elsewhere. Which is far safer for the wasp, obviously.
Check out the video below by the YouTube channel, The Sci Show, on The Wasp That Reprograms Spiders.