Indoor cats require carefully designed environments with complexity, vertical space, and varied stimulation to prevent boredom, frustration, and the health problems chronic stress causes.
Indoor cat welfare requires active owner investment in environmental complexity rather than passive provision of food and shelter. A cat in a bare apartment with nothing to climb, hide in, hunt for, or explore is experiencing a significant welfare deficit even if physically healthy. The behavioral signs of under-stimulation are sometimes misread as laziness or normal cat behavior: excessive sleeping, over-grooming, increased food-seeking, and inter-cat tension in multi-cat homes. Creating an enriched indoor environment requires thinking like a cat: what would I want to climb, where would I want to hide and observe, what prey-like objects can I stalk and capture? The investment is modest and the welfare return is substantial.