i have 3 cats and one of them pooped on the sofa so i need to find out which one and teach them not to because my room smelled like poop for a whole day
agree with Tess. You have to catch them in actual act. And also remember once they did it their they will try to do it their only twice again. so you have very less time.
Taste it then sample all 3 cats poo. The one that tastes like sofa poo is the culprit. Sadly I'm partially serious.
There is really no way to tell which cat poop. You just have to catch them in the act and even with that you are not sure if that cat is the one that poop on your sofa the first time.
I did extensive reading about this kind of behavior in cats before litter training my cat so that I would get it right the first time. I only have one cat but I read about others with more than one and had this problem. One person was on a cat forum for weeks trying to solve the same problem and it turned out that her cats each needed their own litter tray/box, and it needed to be cleaned almost after every use, or asap. The fact is that cats are extremely clean animals and they will sniff for where their own smell is and poop there, then cover it up. So the answer is: the cat the pooped on your sofa is the one that smelled the other cats' smell in the litter box and didn't want to go there, or who was fussy about his or her own litter box being full. Once you get it so that each cat is sure of his or her own litter box and are cleaning it up after each use or as soon as you get home from work, etc., you'll never have a problem again.
there really is no way of telling but you do have to have at least 3 litters 4 is recommended You need to how ever get that cat smell out of the sofa to avoid them doing it again, at least it wasn't urine tho that would have been worse. Just about any super store will have the right chemicals for you. Even if you can't smell it cats probably still can specially if they know.