My boyfriend's spayed female cat (now 7 years old) came to live with us in our new house with my 2 cats 1.5 years ago. His parents were keeping her before & made us take her when she started pooping outside her litter box. We all assumed it was because she missed him, and maybe her old automatic cleaning box which broke (we live in Wisconsin, they live in Texas).

She was fine here until just the past couple of weeks. We keep 6 litter boxes in our basement, which is all concrete floor, except for the long scrap of remnant carpet at the bottom of the stairs near the litter boxes. She has been pooping on that carpet, on the end nearest the litter boxes (about 2 feet away). I just cleaned all of the boxes about 24 hours ago along with the 2 piles of poop she left and now there is another pile in the same place and all of the boxes are still nearly empty.

I am thinking that I might leave her poo there (visitors never go downstairs) and clean the litter boxes every other day so that they're still cleaner than where she's leaving the piles.

Does anyone have a suggestion to give her the idea that this is not appropriate? I really don't want to do anything to force her into pooping upstairs on the new capet in the new construction house.

Thank you so much for any help!
Erin