I suspect in WiaB, they're not spiders, but facehuggers. That's why Helen's ballooning, she's got a chestburster growing inside her. They had crawled away after laying the eggs, and that's why they die so easily. No, that kind are not native to the area Willi. Maybe also like the Alien franchise in SG the spiders have been more normalised, so they're no longer as weird, just albino and orange like some pure abstract idealised spider form, cross specied with a dog (Summer going ewww no bumbum because of doggystyle spidering)