The best minds in veterinary behavior medicine struggle with this problem in cats. We’ll start off by saying that it is far more likely to be rooted in stress/change/anxiety than in your cat deliberately engaging in vendetta. Furthermore, there may be physical causes, too. Or, it might have started with stress or a physical problem, and now he is learning to enjoy the place behind your sofa as his latrine. Once discovered, this habit should be vigorously investigated and treated, as each episode outside the box reinforces the habit. We successfully treat many of these, but also rely on the services of behavior specialists for some patients.