I get spiders in the bathroom all the time. I don't know about crawling through the pipes, though. I think they just get in through tiny cracks in the house that you're not aware of. I just get the harmless daddy longlegs types, and as we respect life, we carry them outside on a newspaper. (Not me, I'm arachnophobic, that's what husbands are for). He'll pick them up by their bungee cord and toss them out the front door. I could never do such a thing.
I get all sorts of things in this house, courtesy the cats.
Because I don't want my deafness to imperil the cats, I'm compelled to leave them free entry-and-exit, like in case there's a fire I don't hear, and so the cats can get out, saving themselves.
This means that when I bring someone over, I have to first rush into the house and inspect things before the guest gets out of the car, in case the cats have left something awkward, so that I can remove it before the guest comes inside.
One time, one of the cats brought in a rabbit, and eviscerated it in the bathroom. It was a small rabbit, maybe circa 8-10" long, but man, it had guts that would've stretched ten miles, it seemed.
It was a quick clean-up job; one is used to such things.
Another time, I walked inside and almost stepped on some sort of brown snake, maybe about 5' long (but not very thick). I dunno what kind of snake it was; rattlesnakes are the only poisonous snakes known in Nebraska, but it wasn't one of them, because I live somewhat east of their terrain. I picked it up by its tail and flung it out the back door.
You know, around here, I have this odd reputation of being a "city boy," because I spent 20 years of my adult life in cities--Lincoln, Omaha, Allentown, and the Newark metropolitan area--but really, I think I proved a long time ago that I'm enured to the country.