I have three cats, two boys and a girl, seen here:
The girl cat is the one we're having problems with, Cassandra. She's the black cat in the center of that photo. For some reason, she keeps finding places to pee that we don't want her to pee. Initially, I thought the problem was not enough boxes in places where she wants to have her smell, so we added some boxes and moved them all around downstairs to the areas she likes to pee. (We have four total litter boxes for three cats, which is the recommended amount of boxes) That didn't fix the problem, so we thought next that the issue was that she doesn't like covered boxes, so we removed the covers from all boxes and it actually seemed for a little while that that had fixed it, except that last night I found a cardboard box full of electronic parts that she had been using as a pee spot, despite the four boxes. I removed that box, cleaned the electronic parts and put them in a new box, then put that box in the garage where she can't get at it. Only to find this morning that she peed in that corner where the box had been (not two steps away from where the actual litter box was).
As far as we can tell she's not having any medical bathroom issues. She never poops in these spots, only pees, so it seems that spreading her scent is the goal. The other two cats, Garak and Alistair, are not having problems with where to pee, even though Alistair is our cat that has the most anxiety issues personality-wise. We have not had any other animals in our yard our house recently, although about two months ago some puppies from our next door neighbor did get into our yard. They haven't broken in again since and Cassie did not seem to mind them at the time.
As far as cat furniture, we have two large cat trees (the one in the picture is the downstairs one), as well as two smaller cat trees that are basically just cat beds, seen here with Alistair:
I'll also admit that I have a lot of boxes still around from when I moved from my apartment to this house. That box of electronics was one of them that I finally emptied out and put everything in a proper place, with the goal to clear out a corner for an armoire that we bought. I have been slowly trying to remove these boxes and put stuff away or sell it, and each time I remove a block I find a new place that Cassie has been peeing that we didn't know about.
I'm at my wits' end trying to figure out what Cassie's issue is. She doesn't behave as if she feels anxious or insecure. She is the boldest of our three cats and seems to feel free to go where she wants. Her favorite way to lay is belly-up.
She does tend to scratch at doors that we close on her, but only when we are on the other side of those doors. We do have rooms that we close off to the cats, and one is notably a back storage room that we closed off permanently to her because it now smells so strongly of cat urine that I don't know how to get it out aside from removing the carpeting.
Cassie seems like she's had a peeing problem since we've had her. We got her as a 6 month old at the same time we got Alistair. @Strikor
was not living with me then, so I had to leave both kitties alone during the day in my bedroom, and I wonder if that being left alone is part of her insecurity. Though that was the entire reason I got two cats, so that they wouldn't be lonely during the day. Strikor did move in about a month after I brought them home, so I'm not sure that being left alone during their kitten-hood is having an impact a year and a half later. I added our third cat, Garak, around July of last year. Cassie gets annoyed with Garak for attacking her when she doesn't want to play, but she seems happy with him otherwise. She will groom both Alistair and Garak.
Between us two humans, Cassie is most strongly bonded to me, though she does love Strikor too and lets him pet her. I considered whether it was the fact that I go to work during the week that bothers her, but Strikor pointed out that she does her morning "bad pee" whether I'm here or not.
So, I feel like we have covered the bases as far as what internet cat lore suggets: Plenty of cat furniture for her to rub against and leave her scent in an acceptable way, plenty of litter boxes for her to pee in and leave her scent that way, plenty of interaction with both humans and cats so she feels secure. What are we missing?
Sometimes I think she dislikes how many boxes of stuff I still have around that need to be emptied, but then it always seems like she has an episode once I clean something out (like the aforementioned box). She's our mystery kitty.