If you thought anecdotes about my kids were bad, how about anecdotes about spiders?
I wrote a book about ants, but I know nothing about spiders. And indeed for the thirteen years I spent Manhattan, I don't think I saw a single spider in the two apartments I lived in. (One of the rarely-mentioned side benefits of urban living -- aside from all the walking -- is the lack of bugs, assuming you don't have cockroaches. I go to visit my parents in suburban Washington during the summer and I feel like I'm in a rain forest.) But here in the wilds of Brooklyn, we have spiders, mostly in our garden, but occasionally in the house itself.
This is the second September we've spent in this house, and I've now noticed a very interesting pattern. Right around September 15, a spider will reliably start building a web between the two rails on the little smoking balcony that leads to the stairs down to our garden. You can knock the web down; you can kill the spider; you can have a heavy rain wash it all away -- whatever you do, the next morning, a spider will have spun another web in the same spot.
Now, I can see that this is an ideal location for bug catching -- it's elevated about fifteen feet above ground, with few obstructions around it, and the two railings supply a perfect frame for the web itself. I can see the merits of the location, but I'm, you know, smart. How does the spider know? Do spiders do scouting missions? Can they assess a location before building the web? This is clearly not a swarm intelligence thing -- like ants optimizing routes to a food source -- because there's just one spider doing the analysis. All you arachnophiliacs out there, please explain what's going on...