We have a fairly recent (3 months) new household of multiple cats who were all adults when we united the households. Things went along without much of a hitch - some hissing from the antisocial cat, but no real fighting. Now, however, all of a sudden, some unknown kitty is peeing on our bed at least once a week. What can we do about this? We don’t even know who the culprit is, as we’ve never seen them in action. Anyway to identify who’s doing it and stop the behaviour - 'cause that’s just nasty!
Here’s a start. I love that site for cat advice.
That indeed is a very good article. I did not read it all, so in case it did not cover it, you should consider more than one litterbox if you have not already done so.
How many is “multiple cats” anyway? 
If more than 3-4, I think two litterboxes at least would be helpful, and appreciated by the cats.
Meanwhile, maybe cover the bed with a large sheet of plastic?
Good luck
Close the door to the bedroom?
Unauthorized pee-age is of course the larger problem, but the more immediate concern for me would be not allowing anyone to pee on my bed.
We have 4 cats, and two litterboxes, on opposite ends of the house. They both seem to get used. I think the cats are going to get banned from the bedroom, as Jodi suggested, at least for the time being. Mind you, they’ll probably just find somewhere else to pee. This is discouraging. Four cats is just too many.
I’d put in at least one more litterbox. The typical advice is that you should have one more box than your have cats, but with 4 cats that’s usually not workable. Still, depending on how big the house is, how far apart your boxes are, and how far the bedroom is from either box, it may be a distance issue. Or with 2 cats per box, it may be a sanitation issue. Some kitties get ahem pissy about their box not being up to their standards of cleanliness and respond by finding a more pleasant spot for their business. Another box might solve the problem.
Of course, there’s an equally large chance that someone is unhappy with something you’ve done. It doesn’t seem terribly likely that it’s over combining the households since you had three months of peace between then and now, but it’s possible. Cats are, after all, weird about what bothers them and when. Has anything else changed around the house? New/rearranged furniture, new schedule, change in food or type of litter? Cats can and do rebel against all of these things; my aunt has one that, when she works extra hours during the busy season, starts to chew up her shoes.
As for how to find the culprit, it’s going to be much harder with 4 cats. What we typically suggest is to lock them in separate parts of the house and see where, if anywhere, the pee shows up. It’s a lot easier with 2 kitties, for obvious reasons. Once you have the culprit in hand, schedule a vet appointment to look for a urinary tract infection just to make sure there’s not a biological cause for the problem. If the cat needs antibiotics, all the door closing and extra litterboxes in the world won’t stop the peeing.
Expanding on the last post -
My cat did this when he had a urinary tract infection. He peed in the bed when I was in it!
The vet’s theory was, it was painful when the cat used the litterbox. That meant the litterbox was bad, so he avoided it. Instead he held it in until he just couldn’t anymore, which meant peeing wherever he was.
What kinds of personalities do your cats have? I knew my cat wasn’t peeing on the bed to “punish” me, or to show displeasure. He just doesn’t have that kind of personality. On the other hand, I once had a cat who would pee right beside the litter box, then turn around and look you in the face. It was her way of saying the box was too dirty.