I feel like every day I kill two spiders in the exact same spot as the ones I killed the day before. I always find them where the wall meets the ceiling on a very specific wall inside my house. They look like they're dead or sleeping. I kill them before I go to bed, and then in the morning there are two more there in almost the same spots! I don't *think* there are webs there. Why do they keep coming back to the same spot, and why in groups of one or two?
Spiders will be hard at work creating new nests every spring. We see this all over so what you are experiencing is no surprise. They love to build these nests in two main locations: baseboard floor molding and up high around crown molding. Outside spiders commonly nest around windows, door frames, attic vents and under eaves. My guess is you have had some living in these areas over the years and from there they've migrated inside the home.
Once they get inside, they'll live in attic spaces, basements and crawlspaces or directly enter living areas from the outside. In homes which provide good attic spaces, we find spiders commonly appearing up high, along the ceiling perimeter, much like you describe. And since web building spiders don't much like moving around, they'll use the first location they find when migrating. My guess is a new supply of spiders is entering your living spaces every day or two and when they find vacant areas (where you just killed 1-2), they decide to grab and use this space. I also suspect more are active but might be missed. The ones up high are probably the easiest to see which is why they seemingly always appear in this one location.
Why they choose this specific location is a bit more complicated. In most cases it's due to wind and light levels. I know there probably isn't any "wind" in your house but remember, to a spider any air movement is wind. Web makers are trying to catch prey and where air is moving is where they expect food to be present. Ceiling lines are great locations for this – as are flooring baseboards – which is why these two areas commonly see activity.
At this point I suggest some control measures put in place which will prevent this problem from happening. If you review our SPIDER CONTROL ARTICLE, you'll learn several treatments that can be done which will help. For your situation, I'm thinking you should start on the outside with a good barrier application. Apply some DELTAMETHRIN all the way around the home focusing your attention on the spots where sopiders are likely to enter. These will probably be under the eaves, around windows and by soffit vents. Attic vents are another great entry point so don't rule them out. The key to your outside treatments is get up as high as you can reach as all areas of your home are likely entry points.
Inside the home be sure to treat attic and crawl spaces if you have any. You don't mention this but my guess is you do and I also suspect these areas are involved. A good dusting with the DRIONE DUST will take care of this area and treatments last 6-12 months so you'll achieve long term protection from your effort.
Lastly, in the living spaces, apply the PT-PHANTOM AEROSOL. I find this works the best in the home mostly due to it being odorless and dry to the touch when applied. I have hardwood floors so spraying a liquid or most any aerosol can be messy. But the Phantom goes on dry and is invisible when applied properly. For me this is important as I get to treat my house without making a mess. And I find treatments last 1-2 months. In the spring I do a treatment March-April-May and then I don't find any more as long as I stay on it every 45 days till Christmas. Inside the house spiders can remain active all year long but we do find treating January and February isn't needed. For you the Phantom would be ideal for treating up high where you seeing a recurring problem. If you treat the area monthly, you won't see any return and combined with the other treatments I listed above, you should be able to stop them altogether.
Here are direct links to the information and products mentioned above: