You know the phrase “no good deed goes unpunished”?
Well, here goes ― altruists who place unwanted house spiders outside their home instead of killing them may not have a better impact than seemingly cruel bug-smashers.
In a recent TikTok sharing “un-fun facts”, app user Alex Falcone shared that “every spider you’ve ever carefully covered with a cup and put outside died outside that day, probably.”
Science has his back, too (oh, dear).
What? Why?
Well, it sounds a bit glib, but ― would you like it?
If the answer is “no, I live in the UK; the weather is relentless, and we’re not evolved to live outdoors” well, that’s basically what’s happening here.
Only about 5% of house spiders ― the clue’s in the name ― have ever been outdoor spiders, per Seattle’s Burke Museum.
“Some house spider species have been living indoors at least since the days of the Roman Empire,” they say.
“If the spider is a native to the area, it will likely be able to survive outside. But if the spider is a transplant that’s become a house spider — even if its ancestors made the voyage to the ‘new’ place decades to hundreds of years ago — odds are, the spider will perish outside,” Rob Crawford, the curator of arachnids at Seattle’s Burke Museum, explains.
Even if your spider is hardy enough to weather the outside elements, the British Arachnological Society (BAS) warns that “the ‘outside’ is not their habitat and it is a bit cruel.”
Well, what if I don’t like spiders in my home?
The BAS advises that not only are most homes filled with undetected spiders, but “they do a great deal of good by eating insects that are in your home and, like the insects, form part of the natural history of buildings.”
“So, if you can, learn to live with them,” they add ― but if you must remove them with the cup method, “put in an outside shed, garage or similar place.”
Crawford seems to agree, saying that when spiders ― even those in similar climes to their native lands ― survive outside, it’s usually in a manmade shelter of some kind.
“You would think [a spider species in an environment similar to its original country’s] could survive outside, but we never find it in natural habitats... just [in] man-made habitats, such as buildings, brick piles, junk piles, and retaining walls,” Crawford shared.
“So, it does, in fact, survive to some extent outside of buildings, but always in a man-made shelter.“
Though retired research associate of entomology at the University of California Rick Vetter argues that the outside is “where they came from. They might die, but then again, they might find suitable habitat,” it’s probably not the best bet if you’re concerned about the species’ health.
I, for one, reckon house spiders have become to their potential outdoor ancestors what poodles have become to wolves ― and you know what? Good for them.