Great Pee Mystery of 2015
My son has been sleep walking for years. When he was 6 or 7, he pee'd in one of the drawers where his clothes are kept. Although I dont remember how we determined it, we were sure that was him and not a cat. Fast forward 3-4 years, and he is still sleepwalking once a month or so, sometimes less, lately at least that, but we have no evidence of any pee'ing in his room during those years. To make the mystery (yet, you guessed what is coming) more complex, our cats have very rarely pee'd inappropriately over those years. Mostly they are good. During winter, when our indoor/outdoor is sometimes not happy about going out, if a soft toy was left on the ground, sometimes it was pee'd on. A few times a bath mat was pee'd on. No issues outside of my son's room in months.
My son *has* been sleepwalking a bit more lately. He has also been leaving wet bathing suits lying around with the start of summer camp a few weeks ago. I have not seen the cats in his room. They just dont normally go in there.
I just googled this exciting topic, and learned that there isnt much difference between cat and human pee, except that cat pee smells much worse, more like ammonia. If this is true, I'm leaning towards my son as the culprit, because the ammonia smell of the literbox is hard to miss.