# Spider builds life sized decoys to fool predators **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [July 7, 2009, 5:04am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168 "2009-07-07T05:04:25Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Indian](https://avatars.discourse-cdn.com/v4/letter/i/c0e974/32.png) [@Indian](https://boards.straightdope.com/u/Indian)\ **Post date:** [July 7, 2009, 5:04am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/1 "2009-07-07T05:04:25Z")
New spider species [discovered.](http://news.bbc.co.uk/earth/hi/earth_news/newsid_8135000/8135844.stm) ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [July 7, 2009, 9:26am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/2 "2009-07-07T09:26:23Z")
That’s neat. ---
**Author:** ![Kalhoun](https://avatars.discourse-cdn.com/v4/letter/k/3bc359/32.png) [@Kalhoun](https://boards.straightdope.com/u/Kalhoun)\ **Post date:** [July 7, 2009, 11:38am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/3 "2009-07-07T11:38:57Z")
That kind of thing freaks me out and amazes me simultaneously. It has a freekin’ human-looking face fercrissakes! ---
**Author:** ![Malleus\_Incus\_Stapes](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/malleus_incus_stapes/32/3293_2.png) [@Malleus\_Incus\_Stapes](https://boards.straightdope.com/u/Malleus_Incus_Stapes)\ **Post date:** [July 7, 2009, 7:53pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/4 "2009-07-07T19:53:24Z")
Cool! ---
**Author:** ![JThunder](https://avatars.discourse-cdn.com/v4/letter/j/e95f7d/32.png) [@JThunder](https://boards.straightdope.com/u/JThunder)\ **Post date:** [July 7, 2009, 8:24pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/5 "2009-07-07T20:24:02Z")
Decoy spiders? What next? Clones? ---
**Author:** ![Covered\_In\_Bees](https://avatars.discourse-cdn.com/v4/letter/c/7ab992/32.png) [@Covered\_In\_Bees](https://boards.straightdope.com/u/Covered_In_Bees)\ **Post date:** [July 7, 2009, 8:27pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/6 "2009-07-07T20:27:51Z")
Nature rules! So much small, yet very awesome stuff happens out there. Quick question though, how do the spiders know what they look like? :dubious: ---
**Author:** ![Wile\_E](https://avatars.discourse-cdn.com/v4/letter/w/c37758/32.png) [@Wile\_E](https://boards.straightdope.com/u/Wile_E)\ **Post date:** [July 7, 2009, 8:36pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/7 "2009-07-07T20:36:15Z")
I don’t know why I clicked on a thread with spider in the title. I don’t think I can click on that link, how creepy is it on a scale of 1 to AAAAAGGGGGGGHHHHH??? ---
**Author:** ![Carnacki](https://avatars.discourse-cdn.com/v4/letter/c/b5e925/32.png) [@Carnacki](https://boards.straightdope.com/u/Carnacki)\ **Post date:** [July 7, 2009, 8:44pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/8 "2009-07-07T20:44:38Z")
> [@Wile\_E](#): > > I don’t know why I clicked on a thread with spider in the title. I don’t think I can click on that link, how creepy is it on a scale of 1 to AAAAAGGGGGGGHHHHH??? Somewhere between 3 gray hairs and 50 heebie-jeebies. ---
**Author:** ![Scissorjack](https://avatars.discourse-cdn.com/v4/letter/s/c67d28/32.png) [@Scissorjack](https://boards.straightdope.com/u/Scissorjack)\ **Post date:** [July 8, 2009, 4:32am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/9 "2009-07-08T04:32:56Z")
> [@Covered\_In\_Bees](#): > > Quick question though, how do the spiders know what they look like? :dubious: Because the ones who produce decoys which don’t look like themselves tend to be selected against, whereas the good model makers have a better chance to survive, reproduce and pass on their genes. You might as well ask how a spider knows how to spin a web. ---
**Author:** ![Indian](https://avatars.discourse-cdn.com/v4/letter/i/c0e974/32.png) [@Indian](https://boards.straightdope.com/u/Indian)\ **Post date:** [July 8, 2009, 4:36am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/10 "2009-07-08T04:36:26Z")
> [@Covered\_In\_Bees](#): > > Quick question though, how do the spiders know what they look like? :dubious: Even I am curious .:eek: ---
**Author:** ![wolfman](https://avatars.discourse-cdn.com/v4/letter/w/a8b319/32.png) [@wolfman](https://boards.straightdope.com/u/wolfman)\ **Post date:** [July 8, 2009, 12:07pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/11 "2009-07-08T12:07:44Z")
So there. The huge piles of clothes and books and random crap on my floor are not me being a lazy slob. I am simply employing and advanced evolutionary defense to decoy would be predators. [sub] And it’s working too, I haven’t been eaten by a wasp yet :)[/sub] ---
**Author:** ![Black\_Sunshine](https://avatars.discourse-cdn.com/v4/letter/b/ce73a5/32.png) [@Black\_Sunshine](https://boards.straightdope.com/u/Black_Sunshine)\ **Post date:** [July 8, 2009, 4:51pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/12 "2009-07-08T16:51:04Z")
Great. Thanks. Now I’m afraid to walk to my car for lunch. My car could be a spider. My sandwich could be a spider! I COULD BE A SPIDER! ---
**Author:** ![Bookkeeper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bookkeeper/32/281_2.png) [@Bookkeeper](https://boards.straightdope.com/u/Bookkeeper)\ **Post date:** [July 8, 2009, 6:01pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/13 "2009-07-08T18:01:08Z")
> [@Black\_Sunshine](#): > > Great. Thanks. Now I’m afraid to walk to my car for lunch. My car could be a spider. My sandwich could be a spider! > > I COULD BE A SPIDER! Quick! Smack yourself with a rolled-up newspaper! It’s the only way to tell for sure!! ---
**Author:** ![The\_Devil\_s\_Grandmother](https://avatars.discourse-cdn.com/v4/letter/t/74df32/32.png) [@The\_Devil\_s\_Grandmother](https://boards.straightdope.com/u/The_Devil_s_Grandmother)\ **Post date:** [July 8, 2009, 6:40pm UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/14 "2009-07-08T18:40:13Z")
“…spiders in the same genus decorate their webs with material such as detritus, plant parts, prey remains…” ewuuu! [Reaver](http://en.wikipedia.org/wiki/Reaver_(Firefly))spiders! ---
**Author:** ![arachnologus](https://avatars.discourse-cdn.com/v4/letter/a/dc4da7/32.png) [@arachnologus](https://boards.straightdope.com/u/arachnologus)\ **Post date:** [July 15, 2009, 6:19am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/15 "2009-07-15T06:19:49Z")
> [@indian](#): > > New spider species [discovered.](http://news.bbc.co.uk/earth/hi/earth_news/newsid_8135000/8135844.stm) 1. Neither of the species mentioned in the article is actually new. Both were named more than a hundred years ago: _Cyclosa confusa_ in 1906, _Cyclosa mulmeinensis_ in 1887. 2. The behavior described is not a new discovery; it was discussed in a book by W.S. Bristowe (founder of the science of spider ecology) in 1941. The only thing new here is actually counting visits of wasps to the webs to test how well the “decoys” work to protect the spiders from predation. But trust news media to distort science for the sake of a sound bite. Which is not to say that these gentlemen in Taiwan are doing trivial work; quite the contrary, it’s always worthwhile to get quantitative data on something that was just a qualitiative observation before. They’re not responsible for what the news media say. Many other species in the genus _Cyclosa_ do something similar to this; including _Cyclosa conica_ which is found in much of Europe and North America. Every so often I get a call or an email from someone who noticed a _Cyclosa_ web, with its string of decoys, for the first time and marvels about how cool it is. And that’s right, they are cool! ---
**Author:** ![Indian](https://avatars.discourse-cdn.com/v4/letter/i/c0e974/32.png) [@Indian](https://boards.straightdope.com/u/Indian)\ **Post date:** [July 15, 2009, 7:10am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/16 "2009-07-15T07:10:59Z")
Sir, with your user name you are going to scare some users here 😉 This is the straight dope and we need experts . But, how do the spiders know their own shape ? :eek: ---
**Author:** ![arachnologus](https://avatars.discourse-cdn.com/v4/letter/a/dc4da7/32.png) [@arachnologus](https://boards.straightdope.com/u/arachnologus)\ **Post date:** [July 15, 2009, 9:22am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/17 "2009-07-15T09:22:18Z")
> [@indian](#): > > Sir, with your user name you are going to scare some users here 😉 > … > But, how do the spiders know their own shape ? :eek: I have to assume that arachnophobic users will only go to a thread with “spider” right up front in the title, if they’re also masochists. 🙂 Or, to be more charitable, perhaps they’re trying to cure themselves by exposure therapy, a very worthwhile objective. And your question was already answered by user Scissorjack, who clearly knows something about evolution. But to rephrase - it’s not necessary for the spider to **know** anything (which is a lucky thing for the spiders, because they are not self-aware). The spiders are performing a series of pre-programmed actions which have been hard-wired into their behavior because those spiders that made the best decoys were the least likely to be eaten by wasps, and therefore their genes were passed on. The spider is not consciously trying to replicate its own shape - that’s ruled out both by the fact that spider brains aren’t capable of conscious thought, and the fact that spiders in this particular group (the orbweavers) can’t form images with their eyes, so cannot see what anything looks like. Now, please, before someone asks “how do you **know** spiders aren’t self-aware?” stop and use your 10-billion-neuron brain for a minute. Creatures we know to be self-aware have brains with at least a few hundred million neurons. Spiders have about 30,000. They are far, far less complex than the computer you’re reading this on. Is the computer self-aware? Then the spider isn’t either. ---
**Author:** ![VanillaGorilla](https://avatars.discourse-cdn.com/v4/letter/v/f9ae1b/32.png) [@VanillaGorilla](https://boards.straightdope.com/u/VanillaGorilla)\ **Post date:** [July 15, 2009, 10:01am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/18 "2009-07-15T10:01:55Z")
> [@arachnologus](#): > > Is the computer self-aware? Then the spider isn’t either. Actually, I think my computer might be. It has yet to make any decoys though. ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [July 15, 2009, 10:04am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/19 "2009-07-15T10:04:46Z")
What do orbweavers do with their eyes? ---
**Author:** ![arachnologus](https://avatars.discourse-cdn.com/v4/letter/a/dc4da7/32.png) [@arachnologus](https://boards.straightdope.com/u/arachnologus)\ **Post date:** [July 15, 2009, 10:24am UTC](https://boards.straightdope.com/t/spider-builds-life-sized-decoys-to-fool-predators/502168/20 "2009-07-15T10:24:58Z")
> [@Indistinguishable](#): > > What do orbweavers do with their eyes? Orbweavers (and other web-making spiders, as well as some hunting spiders) sense light and dark and movement with their eyes. This gives them a day-night cycle and some visual warning if something is moving right in front of them. There are 20 or fewer cells on each retina, too few to form a useful image.