# Why do spiders bite humans? **URL:** \ **Category:** Factual Questions\ **Created:** [November 19, 2009, 10:50pm UTC](https://boards.straightdope.com/t/why-do-spiders-bite-humans/518214 "2009-11-19T22:50:49Z")\ **Posts on this page:** 4\ **Page:** 2
**Author:** ![gonzomax](https://avatars.discourse-cdn.com/v4/letter/g/e8c25b/32.png) [@gonzomax](https://boards.straightdope.com/u/gonzomax)\ **Post date:** [November 24, 2009, 12:41pm UTC](https://boards.straightdope.com/t/why-do-spiders-bite-humans/518214/21 "2009-11-24T12:41:29Z")
> [@arachnologus](#): > > On the original post: as has already been pointed out, probably few if any of your “spider bites” are spider bites, or indeed the bite of anything. If you don’t see any biting organism, don’t be so quick to assume it’s a bite: some of the non-bite conditions can be serious, occasionally even life-threatening! See [my page on the topic](http://www.washington.edu/burkemuseum/spidermyth/myths/asleep.html), also these: > [Causes of Necrotic Wounds other than BRS Bites | Spider Research](http://spiders.ucr.edu/necrotic.html) > [http://www.ama-assn.org/amednews/site/free/hlsa0805.htm](http://www.ama-assn.org/amednews/site/free/hlsa0805.htm) > [It’s Not a Spider Bite, It’s Community-Acquired Methicillin-Resistant Staphylococcus aureus | American Board of Family Medicine](http://www.jabfm.org/cgi/content/full/17/3/220) > [That's No Spider Bite: Antibiotic Resistant Staph Infections Now Very Common - ABC News](http://abcnews.go.com/Health/Story?id=2320020&page=1) > for answers to the question “what else could it have been?” > > The idea that spiders bite people who roll over them in their sleep is also a myth. Spiders’ fangs are on the underside of the spider. The reflex bite that occurs when the spider is being crushed to death by an enormous monster rolling onto it, will be delivered to the sheets, not to you, in the vast majority of cases. > > The idea that you can recognize a spider bite by [2 punctures](http://www.washington.edu/burkemuseum/spidermyth/myths/2marks.html) is also a myth (click link for my page on the topic). > > If your friend didn’t live in the green area on [this map](http://www.washington.edu/burkemuseum/spidermyth/images/loxomap.gif), then what he got nailed by was medical malpractice. See some of the articles linked above, also [this one](http://spiders.ucr.edu/myth.html) and [my page](http://www.washington.edu/burkemuseum/spidermyth/myths/brownrecluse.html#) on the subject. This is one area about which 95% of physicians know almost literally nothing - because they get nothing significant on spiders in medical school. So they do what everyone else does, and blame all mysterious skin lesions on unseen spiders. He was playing golf right smack in that area. ---
**Author:** ![Kenyth](https://avatars.discourse-cdn.com/v4/letter/k/c68b51/32.png) [@Kenyth](https://boards.straightdope.com/u/Kenyth)\ **Post date:** [November 24, 2009, 1:39pm UTC](https://boards.straightdope.com/t/why-do-spiders-bite-humans/518214/22 "2009-11-24T13:39:20Z")
> [@arachnologus](#): > > Certainly it is possible for a large spider (or one with large fangs, like the [woodlouse spider](http://entomology.unl.edu/images/spiders/dysdera1.jpg)) to leave visible puncures, but even in the largest spiders it occurs no more than half the time. I myself have been bitten by a large tarantula (one of the 2 genuine spider bites I’ve ever had, after handling tens of thousands of live spiders) and the punctures were very hard to detect. > > The idea that smaller spiders cannot penetrate the skin is [yet another spider myth](http://www.washington.edu/burkemuseum/spidermyth/myths/toosmall.html). It’s not that they can’t, but that they very rarely do because they have no reason to. > > The idea that large spiders in the house must have entered from outside is still [one more spider myth](http://www.washington.edu/burkemuseum/spidermyth/myths/comein.html). And with rare exceptions like the brown recluse (found only in a limited area, despite all the foolish rumors claiming that it’s found everywhere), house spiders are not pests. They are beneficial - they **EAT** pests! Very interesting that small spiders can bite as well. I realize that most spiders are shy and unagressive towards humans. The only one’s I’ve personally had problems with are the wolf spiders. I appreciate your respect for spiders, and I don’t personally believe them to be the worst of venomous pests. Far from it. Hornets, Yellow Jackets, Stinging Ants, and Paper Wasps hold that trophy IMO (nasty, agressive, things!). At the same time, neither my children or wife much like them, so we won’t be sharing the house knowingly with visible spiders anytime soon. Sorry. ---
**Author:** ![minlokwat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minlokwat/32/2844_2.png) [@minlokwat](https://boards.straightdope.com/u/minlokwat)\ **Post date:** [November 24, 2009, 2:54pm UTC](https://boards.straightdope.com/t/why-do-spiders-bite-humans/518214/23 "2009-11-24T14:54:26Z")
> [@gonzomax](#): > > A friend got nailed by a Brown recluse. It was ugly with skin atrophy around the bite. As a bonus it would flare up every couple years and look like it had bitten him again. It was ugly and returned sporadically for over 10 years. The wound or the spider? If it’s the latter, man, that’s one pissed off insect. Arachnid, whatever. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [November 24, 2009, 11:09pm UTC](https://boards.straightdope.com/t/why-do-spiders-bite-humans/518214/24 "2009-11-24T23:09:05Z")
As I was reading this thread this morning I noticed a rather large spider on my wall. So I started a new thread to help identify it. Spider experts welcome: > **[Help identify this spider](https://boards.straightdope.com/sdmb/showthread.php?t=541282)** > > I did not want to hijack the other thread here about why spiders bite humans here: http://boards.straightdope.com/sdmb/showthread.php?t=540624 But this morning as I was reading that very thread I noticed a rather large spider on the wall right... [Previous page](https://boards.straightdope.com/t/why-do-spiders-bite-humans/518214.md?page=1)