European House Spider – Tegenaria domestica
Also known as “Barn Funnel Weavers”, “Sink Spiders” and “Those Monster Hairy Spiders That Run Like The Wind”.
This is clearly a female, because she has thin, tapered pedipalps and is pretty good-sized. Now, as it turns out, we have the same ones in our house – this next one I caught in our sink, and it looks an awful lot like the one Michelle photographed. This time it is photographed from above, so you can see the patterning on the abdomen:
I would warn that the abdomen pattern is not a good ID feature, because sometimes these spiders are dark enough that you can’t see the pattern. The main thing is that they have short spinnerets compared to most other funnel-weavers, and they have smaller eyes than wolf spiders.
I mean, if this was a wolf spider, then zooming in on the face like this we’d see a pair of huge, intent eyes staring back at us, not just these little myopic things:
As you might guess from the name, these are not native to North America. They evidently hitch-hiked over with the colonists coming here from Europe, and are now a widespread cosmopolitan species. They look similar to the so-called “Hobo Spider”, which is also an import, but that one doesn’t live here (yet), and it doesn’t have the striping on the legs that this one does.
European house spiders are adapted to your house, so throwing them outside isn’t doing them a kindness – they didn’t come in from the outside, and throwing them out just means they’ll probably die when it gets cold. They look big and mean and hairy, but it takes a lot of effort to persuade one to bite (to the point that I’ve never successfully goaded one into biting me). One thing that they do do, is eat other vermin in the house (roaches, carpet beetles, flies, crickets, ants, you name it).
Supposedly, the immatures and females build funnel-shaped webs in the corners and pretty much stick with them, while the mature males roam around from web to web looking for mates. That’s what I keep reading, but that’s not so much what I’m seeing. The immature spiders and female spiders seem to roam around a lot too. I find them in webs sometimes, but a large part of their population seems to have become more free-living, actively hunting the way that wolf spiders do. Which is why people frequently mistake them for wolf spiders, even though they aren’t that closely related. I think what is happening, is they are speciating. They are adapting to our household environment, and radiating into new niches. Building a web is a great strategy in a barn or in the grass, but in the house it just calls attention to yourself, and then the brooms and vacuum cleaners come out, and whoosh! Gone! I think there is a lot of selective pressure driving these spiders to minimize their use of webs, and over time I think they are going to get more and more like wolf spiders.
 Actually, I already had a picture of one of these. But, it was only my second posting, and it really wasn’t a very good picture or writeup. Since this is one of the spiders that lives in practically everybody’s house, I figured it warranted a more thorough treatment.
 I don’t think this one is on her print sales site, but don’t let that stop you from seeing what else she has there.
 Michelle also mentioned that this picture was taken just shortly before her cat pounced on the spider and ate it. So, for all the people who want to know how to get rid of spiders in the house, there you are – get a cat.
 Come to think of it, they probably came over on the Mayflower. I should have posted this on Thanksgiving! (smacks self on head)
 I’ve been throwing around the term “cosmopolitan”, and I’d probably better clarify what I mean by it, and how it is different from just “non-native” or “invasive”. Non-native species are anything that came in and has managed to carve out a niche in the local ecosystem, however tenuous. Invasive species are the non-native species that, for whatever reason, are unusually successful and start displacing other species. Cosmopolitan species are a bit different – they aren’t taking over a niche in the local ecosystem. Rather, they are depending on us to create a niche for them, by building houses and other structures that they can move into, or by cutting down the forests to make lawns, or plowing up the prairies to make fields. They live everywhere, but only because we live everywhere. If for some reason people stop living in an area, and abandon everything to revert back to what it was before, then in most parts of the world these cosmopolitan species will then find themselves in an uncongenial environment and die off. Similarly, they don’t move into an area until we do. I expect that a lot of cosmopolitan species live in Antarctica, but only for as long as we maintain the bases there. If we ever shut them down, then pffft! they’re gone.
 Way back when I was an undergraduate, my housemates had a tendency to leave dirty dishes with food on them scattered around the house. And, of course, the house was an old, decrepit structure that didn’t so much keep out the wildlife, as give it shelter. This of course lead to a tremendous ant problem in the spring, plates and bowls were sometimes completely black with ants within a few minutes. Then, along about June, there was a massive population explosion of European House Spiders, and within a couple of weeks – no more ants. Of course, then we had these big, fat spiders scurrying around, which freaked out my housemates much more than the ants had. Suited me fine, though.