I just got an 8 month old cat at the shelter about a week ago. Right from the beginning he has always used the litter box without fail. BUT tonight he decided to go into my duffle bag that was on the floor and poop in it! Why did he do this? Is this likely to become a habit? And what do I do to keep it from becoming a habit?
Added from comment: The litter box was clean and I know he was not feeling afraid to go to his litter box because it is by his food and water bowl and he went in there to eat right before.