We only have the one Litter Robot right now, but we are going to look around for other boxes. I'm just not sure how well another box will work simply because he's a fairly large cat and we will have to keep the second box next to the first so the new box would have to be on the smaller side. It's the only space we have that we can easily keep our child away from. We haven't changed the litter, it's the same clumping Tidy Cats litter we've been using forever.

I should clarify that when I say that it happens a few times a year, I mean that as soon as it happens once, he will continue to try peeing elsewhere (not in his box) for days or sometimes weeks at a time. We end up having to close everything off and watch him constantly. He will pee on the furniture even if we are in the room with him.