First, the average time it takes a spider to build a web is an hour or less, so the existence of the spider and web is in no way an indication that the room has not been cleaned. Only that it hasn’t been cleaned in the last hour.
Second, we have bugs in the south. Guarantee you there have been spiders in all the rooms at some point, and they are probably in a lot of the rooms right now. You just don’t know they are there because most like to hide away or come and go without you noticing.
We have a nice house in town. Not even a wooded area. It gets regular pesticide treatments. We still get spiders inside. I’m sure if I went looking, I could probably find one right now. No matter how hard you try. You can’t keep 100% out. This is completely normal in the south.
If the thought that you might find one somewhere inside freaks you out, you probably need to rethink visiting the south.
They come in through cracks / seams around doors and windows and up pipe drains. There’s not much you can do to keep them out. Guarantee they are in restaurants and rides as well. They are everywhere.
If you are really worried, here’s what you do.
Shake everything you pick up out before putting it on. That’s usually how you get bit. You pick up something, a shirt, jacket, blanket, shoe, toy, etc that a spider has crawled inside of, and you aggravate it by moving it around or touching it by accident, so it bites you. They don’t come for you. They aren’t attack dogs. People aren’t spider food. If it is in the web, it will most likely stay there unless you disturb it. Just be aware before grabbing something, and you should be fine.