As I mentioned (funnily enough) in a post about cat litter, cats have a much more acute sense of smell than we humans do. That means cans can certainly smell what they're leaving behind in a box. And it almost certainly means they can smell that stuff when they head back to the box, unless some clever human has intervened.
Several of the cat litters I've sampled lately for my cats claim to provide such fabulous odor control that one doesn't need to clean the box more than once or twice per week. But the question is: What does your cat really think about that?
In my volunteer work with Willamette Humane Society, I often come across little cats that were popped into the shelter due to litter box woes. These guys either wouldn't use the box at all, or they would use it intermittently. At times, that's caused by a medical condition. But often, it's due to lax cleaning processes.
I've seen several intake forms in which the humans report that they clean/scoop the box just once per week. That means they're asking the kitty to head back to a horrible box over and over again. And I can't help but wonder if these families would still have their kitties if they had been a little better about cleanup.
When these cats come to the shelter, they have clean boxes at least 2x per day. There's a swapout in the morning, and one at night. And during open visitation hours, the volunteers empty any dirty boxes (so the air smells nice). Like magic, many of those litter box problems that brought cats to the shelter go away. A clean box tends to mean a clean kitty. And in the shelter, these cats get the clean boxes they want.
So how often is often enough for kitties that aren't in the shelter?
In my household, every box is scooped twice per day. There's a scoop after breakfast, and a scoop before bed. Then, once per week, every box is scoured and cleaned, and the litter is refreshed.
These are some damn clean boxes. And guess what? My cats use them.
Sure, cleaning out boxes and dealing with cat leavings is icky. It's not the nice part of having cats. But, walking through cat puddles or dealing with stressed animals is equally bad. For me, cleaning is better.
How often do you scoop and clean? Love to hear about your routines in the comments.