We changed houses this summer, and it seems like we have had far too many spiders showing up in this new house (I’ve killed four or five in five months, and my husband has shooed some more out the door). I was just wondering how many spiders are actually in my house that I don’t see at any time. What do you think - 20? 30? 50?
At least a thousand. Probably many more.
BTW - had you noticed that one in your hair? 
You think you’re being funny, but the spiders in our new house are danglers - I keep finding them on the ceiling or dangling, just about to land on me. Gah.
Why do you kill them? They are quite helpful, you know.
They can go and be helpful outside! That’s my personal belief: you come inside and your life expectancy just dropped Mr. Spider. You stay in the shed, garage or just outside, and you can go your merry way. And we have had some huge spiders outside. Well, huge for Iowa, it was just a little smaller than a tarantula. We took pictures and the bug control place identified it (can’t remember now) and said its bite caused necrosis and it was not natural to IA. I wish we would have killed it, as we have no idea where it went or what happened to it. I hope it didn’t make thousands of baby spiders. ::shudder::
Exactly - inside, fair game. Outside, go live your spidery life with my blessing.
I really resent your discrimination against the myriad “climbers” living in your house - including, undoutbedly, your bedding!
Just want to do my little part to make you feel more comfortable within your skin.
A little more seriously, you are only seeing the obvious ones, which I understand comprise a tiny minority of the spiders infesting your (and everyone else’s) house. Just imagine how many are scurrying around inside the walls, up in the attic and down in the basement, way back in the closets …
Why did I click this thread?
And why are you a bad person?
You may imagine how disappointed I am to find that I may have been passing misinformation. 
So I take back what I said about the total number of spiders in your house. I’m sure there are no more than a handful, and you will soon get rid of them all. (But I meant what I said about that one in your hair. It looks mean - and hungry!) :eek:
Be honest now, don’t you feel where it itches?
The only reason spiders live anywhere is that’s where their food is. Get rid of the spider chow in your house: problem solved. Of course, that is way too much effort–so you have to be happy (?) cursing and smashing our little eight-legged friends.
If by “helpful” you mean they will do the dishes and laundry, then hell ya, bring em on. Otherwise. . .squish.
A spider large enough to be that helpful would not be welcome in my house, thank you. Even wearing a little French Maid type outfit.
Here’s the spider specialist’s answer. (Sorry I didn’t spot this thread sooner). Counting the crawlspace and wall voids, several hundred spiders at least in a typical house. They would belong to anywhere from 5 to 25 different species, depending on how rich a spider habitat your house is (i.e. how many insects and how much moisture is available). Not many would have any tendency to dangle. And practically all would be harmless to humans, unless you live in the quite-small area where the “brown recluse” is common. Even there, genuine spider bites are quite rare (alleged “bites” where nobody saw any spider don’t count).
I once did a comparative census of Tegenaria (European house spiders) in Seattle houses, enumerating the first 50 I found in each house. I never had any trouble finding 50 just of this particular genus, and this was without tearing apart any walls or moving the washing machine.
I’m afraid Otternell is living in a fool’s paradise with the idea “you come inside and your life expectancy just dropped Mr. Spider.” House spiders don’t come inside: that’s one of the myths debunked on my web site. They are different species from the spiders in your yard and garden.
If you actually could make all your house spiders disappear, your woolens and carpets would soon be eaten up by moths and beetles, you could never keep any whole foods in your pantry for the stored product pests, all your books would fall apart from the depredations of the silverfish and firebrats, drugstore beetles would eat your spices, you’d have big flea outbreaks every time one hitched in from the yard dropped by a wandering raccoon or cat, every mosquito that wandered in would be sure to find you… Would it be worth it?
Well, if you put it that way…
Okay, the ones I don’t see get to live, and I won’t go looking for them. And perhaps I was exaggerating about all the dangling - mostly they are up on the ceiling. The one that was dangling was right near my face - that left quite an impression on me. 
In my experience, there are some questions it it better not to know the answer to. In that category are whether your parents truly loved you or only the idea of you; whatever happened to that girl you kissed on the last day of 8th grade and were passionately in love with but never saw again; and the exact number of spiders in your house.
Not sure in total but I manage to remove one-two hobo spiders a month from the place. My wife has been bitten once by one.
Thank you for the info, arachnologus. Ignorance on my part fought.
My grandmother told me when I was 8 that spiders were useful and should not be killed. I like spiders, but when one gets to be too bothersome (e.g. a large spider dangling in the middle of my kitchen when I’m expecting arachnophobic guests), I tend to pick it up and put it outside. I thought I was giving it a chance. From now on, I’ll stick it in the attached garage or our cold-room/larder.
No fear or squeamishness regarding spiders, but if a wasp makes its way into the house, I become a blubbering idiot.
Think about it this way: you have spiders in your house because your house has lots of spider food. Now me, I’d WAY rather see the spiders than be overrun with what the spiders eat. I rarely see them, but I like 'em. They’re doing a good and useful service.
I’ve never thought that spiders come into the house in the Autumn, but I’ve seen spiders come into the house in the Summer.
I’ve never knowingly seen a hobo spider, but I’ve seen a few that are about the right size and shape. There’s no way for me to know what kind they are. Mostly I see ‘daddy long legs’ (Pholcus phalangioides) and what I call ‘garden spiders’ (since they look the same as the ones in the lawn). Sometimes I’ll find a ‘Giant house spider’ (Tegenaria duellica). These are brownish, and about 30 mm to 50 mm long in their resting position. If I flip over the couch, I’m sure to find at least one false black widow (Steatoda). No doubt I’m reclining over a couple right now. I’ve never seen an orb weaver or jumping spider in the house.
This house is approaching 76 years old and is in a wooded area. Many parts of it, under the house/floors, walls, etc. have been undisturbed for years and years. Good spider habitat. Total floor space is about 1,090 I think. So if there’s one spider per square foot, that’s almost 1,100 spiders in the house. I’ve never seen that density of spiders here; but then there are also the walls and under-furniture spaces to consider, which might in plan-form result in that density. I’m guessing this house has at least several hundred spiders in or under it.
False black widows I don’t care about. Out of sight, out of mind. The others are captured an placed in the Penalty Jar until I take them outside. The way I reckon is this: Spiders lived outside before there were houses. So if I release them outside, they have a chance to find a suitable substitute. Better that than smashing. And if they get eaten outside? Well, then a bird or another spider gets fed.
Depends on what you mean by in the house. If you mean the actual living space, probably a dozen or so total. They like to hang out in the bathrooms, mostly. However, down in the cellar there are probably 50-100 of them. Generally they’re not the biting kind (wolf spiders and one other kind that’s tiny with a fierce bite come in during the summer) so who cares?