Hi, New member here; found the site after a web search looking for help regarding one of our four cats having taken to "pooing" outside the litter tray in all sorts of different places.
I had never heard the term "middening" despite our daughter being a veterinary nurse.
The cat in question is female, six years old and dislikes going outside, to the point of being virtually a "house cat", and as such has a litter tray permanently.
Currently, we seem to have solved the problem, simply by isolating her in a small room at night and with a different make & type of cat litter (that she has access to during the day too). Meanwhile a sample of her faeces has been sent for analysis, but hopefully nothing sinister will be found and the problem solved...............watch this space!!