Yesterday morning, I saw a spider nestled in the corner of a door frame. It had surrounded itself with a small pocket of web, just big enough to enclose itself. At the time, it looked as though it might be dead: It wasn’t moving at all.
The next time I took a look, about a half-hour later, it had opened up a hole in the top of the pocket, and departed for parts unknown.
So the question is, what was the purpose of this web? It can hardly have been to hide the spider: The web was barely even visible. To protect it against predators while it slept? I’d imagine that anything that would eat a spider would go right through a web without noticing it. To catch food? Anything that got that close, it could just attack with its limbs. A place to lay eggs? But there don’t seem to be any eggs in it, now that the spider is gone.
I think it was to keep bugs from walking on her while she was sleeping. You know how hard it is to sleep once you think that little itch might actually be a bug walking on you?! ;-).
It looks like a Clubionid or sac spider. They make little web retreats for molting, laying eggs, but also just to spend the day. They’re mostly active nocturnal hunters, who use webs exclusively to build shelters not to hunt with. They’re harmless and useful pest controls to have around, but do tend to leave little abandoned web cells everywhere.
OK, so it’s shelter. But what is it sheltering from? I can’t see that web keeping out weather or hostile animals. And nocturnal doesn’t fit when I saw it: It was in the web first thing in the morning, and then left it some time around dawn.
Yup, I don’t know exactly where it went, but I take comfort in the knowledge that it’s around here somewhere, doing its job. Spiders are not feared or dreaded in this household.