## Two industrious spiders, one with math skills

Today we have two overachieving arachnids.

First, from the Torygraph’s picture gallery for today:

The incredible spider’s web which appeared in front of Russell Harding s garage door. A pensioner could not believe his eyes when he stepped outside his front door and almost walked into this spider’s web – which spanned six foot. Russell Harding, 74, was shocked when he spotted the huge web as he went to carry out some early morning work in his garage. The web, which spread the gap between his car’s wing mirror and his shed and had an inch and a half spider sat in the middle.

From Matthew: The spider is a European Garden Spider, and is obviously substantially closer to the camera than the garage door (if not, the spider would be truly immense…) In fact, we could probably work out how far away the spider and the garage food are with a bit of trigonometry. If we assume that the spider is 3 cm long (max) and the panels on the garage door are 12 cm high, what is the distance between the camera and the spider and the spider and the door?

Picture: Russell Harding/SWNS

Also from Matthew:

Another great web, also apparently by a European garden spider, was tw**eted by @MikeWil, from imgur user Reverseloop. This spider found an amazing solution to a major problem. It wanted to slid its web across the top of a garage, but the angle of the roof was so shallow that it couldn’t anchor the web. So in a fit of industrious genius, it found a rock, and dropped that down on a thread, to hold the bottom of the web. As Mike said ‘I’ve never seen anything like it.’

View up to the roof – you can just see the web at the top

And here’s a close-up showing the webbing connecting the thread to the pebble:

You can see more on Reverseloop’s imgur page.

h/t: Roo

1. Posted October 6, 2014 at 10:02 am | Permalink

Might I just say right now that I welcome our new spider overlords.

Surely world domination by rock wielding arachnids can only be a short time away?

• Diana MacPherson
Posted October 6, 2014 at 10:17 am | Permalink

I just thought that ingenious spiders kind of scare the crap out of me.

• infiniteimprobabilit
Posted October 6, 2014 at 11:19 pm | Permalink

Then you’d LOVE this one…
http://en.wikipedia.org/wiki/Web_(novel)

• Diana MacPherson
Posted October 7, 2014 at 6:29 am | Permalink

I had a lot of spiders in my house as a child. They’d come up the pipes in the bathtub even. I used to think that if I harmed them, more would appear. So began my altruism toward spiders. I still put them outside.

Spiders hunting in pacts – I would have nightmares every night.

• Posted October 9, 2014 at 2:50 pm | Permalink

There are some pseudo-social spiders that hunt communally. They’re itty-bitty, but if they stick together they can take down pretty large prey. Solidarity forever!

• SA Gould
Posted October 6, 2014 at 4:51 pm | Permalink

Also had a spider start a web from car roof antenna to brick house wall. I discovered it by feeling resistance as pushed into it with my face. They are also making them *stronger.*

• gravelinspector-Aidan
Posted October 7, 2014 at 6:50 am | Permalink

It beats my metaphorical sock for arguing about the reality of reality.
Does the rock count as having been sufficiently modified to be considered a tool, and thus spiders as being tool-using creatures?

2. Posted October 6, 2014 at 10:13 am | Permalink

‘Tis the season. This is the best time of year in the northern hemisphere for spotting great webs like this, and also lots of interesting sheet and funnel webs closer to the ground. I hadn’t heard of a garden spider suspending stones before, but a number of other spiders suspend various objects, including snail shells. Film buffs might like to know that this garden spider, now known as Araneus diadematus, used to be known as Epeira diadema and starred in a documentary short made by Alberto Ancilotto that was nominated for an Oscar in 1952: http://www.somscrocetta.it/ancilotto/alberto.htm

• Dominic
Posted October 7, 2014 at 2:46 am | Permalink

I have seen webs about 24 in or so across…

3. Posted October 6, 2014 at 10:23 am | Permalink

what is the distance between the camera and the spider and the spider and the door?

Um…not enough…?

The real challenge, I think, is how to properly relocate the spider…or whether one simply reports the car and house to the insurance company as a total loss and move on….

b&

• Diana MacPherson
Posted October 6, 2014 at 10:52 am | Permalink

You mean like this:

• Posted October 6, 2014 at 11:01 am | Permalink

If the spiders and the octopuses ever start working together, we’re all in a lot of trouble.
What do they need all those damn legs for?
A hippo weighs over a ton. Four legs. Why does an itty-bitty spider or a living jello shot with a beak need twice as many legs as a hippo?
Something is up and I don’t like it one bit.

• SA Gould
Posted October 6, 2014 at 4:52 pm | Permalink

“a living jello shot with a beak…” That’s good!

• Posted October 6, 2014 at 11:04 am | Permalink

No, no need to kill the poor beastie…just let it have its new home all to itself. One’s retreat needn’t even be excessively hasty…a more stately pace might be called for….

b&

• Posted October 9, 2014 at 2:54 pm | Permalink

Orbweavers are really easy to catch if you can sneak up on them while they’re on their web. Their first response to danger is often to drop from their web, so if you’ve got a vial or a cup underneath ’em, she’ll fall right in.

Orbweavers dismantle their webs very often (some do it daily). They’ll eat the silk to get back whatever nutrients they can, hide in a retreat during their inactive hours, and make a new web. In short, don’t fret about knocking down a spider’s web, regardless of how beautiful it is!

4. Posted October 6, 2014 at 10:55 am | Permalink

These are examples as to why I adore and admire spiders. I would immediately look for an insect as a justified reward.
I do not know how that rock got suspended, and I am not sure if the description really means that the spider was seen to lower a rock down. If so, then my flabber is very much gasted.

5. Stephen P
Posted October 6, 2014 at 11:04 am | Permalink

Assuming that’s a normal garage door the panels will be closer to 20cm than 12cm. (At 12cm, you’d be hard put to park an E-type in it.) To an engineering approximation the spider appears about the height of a panel, so the distance from door to camera will be about six times the distance from spider to camera.

I can’t immediately see a way of calculating absolute distances though, unless someone can do something rather subtle with the subtended angle of the watering-can.

• Posted October 6, 2014 at 5:05 pm | Permalink

Assuming that’s a normal garage door the panels will be closer to 20cm than 12cm.

Thanks. My own estimate, based on the height of our own garage door, was 25-30cm, but 20cm gives a result well within the range of possibilities.

I love and adore the second example: tool-using among spiders. Mind-blowing.

Like some others here, I’m a big fan of spiders and don’t find them in the slightest creepy or scary. Wasps, on the other hand . . .

6. Posted October 6, 2014 at 11:34 am | Permalink

A couple of weeks ago we had a humming bird stuck in a web built by an overenthusiastic spider. We have a feeder outside the kitchen window and the hummer was splayed out on a web between the feeder and the window. I had to do a double take to understand what was going on. Anyhow it took the fear generated by my approaching to free it for the bird to gather the energy to break out.

• darrelle
Posted October 6, 2014 at 12:01 pm | Permalink

I can’t remember where or what species of spider, but I have seen video of some type of spider successfully catching a humming bird. And I seem to remember that it was said that such behavior was normal for that particular species of spider.

• Diana MacPherson
Posted October 6, 2014 at 1:37 pm | Permalink

Wherever that spider is, I will not be there.

• Posted October 6, 2014 at 2:25 pm | Permalink

Like this? Scroll down. Not for the squeamish. I am going to guess a golden silk spider.

• Posted October 9, 2014 at 2:58 pm | Permalink

It’s not quite “normal” for any spider to eat birds (despite the few tarantulas with “bird-eater” in their common names), but as opportunistic hunters – well, you know.
A few years ago somebody published several recorded instances of spiders eating bats. Spiders are awesome (so are bats).

7. still learning
Posted October 6, 2014 at 12:29 pm | Permalink

That rock proves the great tensile strength of spider web strands. Also, seeing these pics makes me wonder if Charlotte’s Web is non-fiction. 🙂

• Jeffery
Posted October 7, 2014 at 11:45 am | Permalink

Yeah, it looks just like when Spider-man gets a hold of something with HIS web!

8. abram
Posted October 6, 2014 at 12:32 pm | Permalink

Now just how the hell did the spider do that with the stone? Does it qualify as a tool? (The stone, not the spider. Spider is clearly a genius).

9. Posted October 6, 2014 at 1:55 pm | Permalink

I believe that there is a strong possibility that the rock was pulled up from the ground rather than dropped from above.

After all, how many pebbles are conveniently found in rafters at the correct location?

There was probably no intention to raise the stone from the ground, it may have occurred in the process of tensioning the web.

• Prof.Pedant
Posted October 6, 2014 at 3:58 pm | Permalink

I suspect that you are correct….but this still seems to come very close to counting as tool-use by an arachnid. I strongly suspect that arachnids have no self-awareness, so if this is an example of tool-use we can probably assume that tool-use begins with some pretty rudimentary coping with reality.

• Latverian Diplomat
Posted October 6, 2014 at 6:26 pm | Permalink

If Richard’s supposition is correct, it’s purely accidental. The spider was trying to anchor the web on “the ground”. And part of “the ground” moved. The stone was pulled up by the tension in the web.

To consider that to be tool use is to define tool use far too broadly, IMHO.

• Posted October 9, 2014 at 3:00 pm | Permalink

Agreed wholeheartedly. An orbweaver will anchor to anything strong enough to support the web by sending strands out into the wind and hoping they attach to something. This one attached to a pebble! Neat.

• gravelinspector-Aidan
Posted October 7, 2014 at 6:55 am | Permalink

There was probably no intention to raise the stone from the ground, it may have occurred in the process of tensioning the web.

I had been wondering why the spider had hauled the rock off the ground, instead of just tensioning against it. Obviously some tensioning effect.

10. Keith Cook
Posted October 6, 2014 at 2:46 pm | Permalink

Gobsmacked by the rock, that’s one smart arachnid.

11. John
Posted October 6, 2014 at 2:58 pm | Permalink

Here are 2 articles on the mechanics and design of spider webs:

http://jeb.biologists.org/content/216/18/3388.long

For this one copy and paste into Google Scholar then click on pdf to the right:

http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2011.00809.x/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false

• John
Posted October 6, 2014 at 2:59 pm | Permalink

I should have written copy and paste “title” into Google Scholar

• Posted October 6, 2014 at 6:15 pm | Permalink

Todd Blackledge is an author on both of those papers. He’s done lots of important work on spider silk mechanics.

12. gravelinspector-Aidan
Posted October 7, 2014 at 6:58 am | Permalink

I’d estimated the garage door size as being approximately 1m from ground to the door lock, giving about 25cm per panel. For a 3cm spider, that says the door is about 8 times as distant as the spider.
That neglects gravitational lensing by the spider, which is not likely to be a major correction.
Oops, swimming pool time!

13. gravelinspector-Aidan
Posted October 7, 2014 at 7:00 am | Permalink