Self-cleaning litter box for 3 cats, one guarding

With three cats and one box being guarded, you've actually got two overlapping problems — not enough litter box access, and probably one cat (often the youngest or the eldest) being squeezed out. Self-cleaning boxes can genuinely help here: they stay fresher between cleans, which reduces the territorial tension that builds around a smelly, used box, and some models are large enough that a guarding cat can't physically block access as easily. That said, they're not cheap, they need clumping litter, and an 8-year-old cat may take a few weeks to accept the noise and movement. Before I point you anywhere specific — is the guarding mainly one cat bullying another away, or is it more that one box is just getting too full too fast? And what kind of budget are you working with?

That changes things quite a bit. The floor accidents from your 2-year-old are a stress response to being blocked — that's a behavioural issue as much as a litter box one, and the most important fix is separating the boxes so the 5-year-old can't guard both at once. Two boxes in the same corner is effectively one box in cat logic. Before spending anything, move one box to a completely different room. That alone may stop the accidents within a week. Now, should you also upgrade to self-cleaning? With your budget and three cats, yes — it does make sense as part of the solution, but it supplements the separation rather than replacing it.

For three cats with a guarding dynamic and a £500 budget, I'd recommend the Litter-Robot 4. It's the most reliable self-cleaning box available in the UK right now, and for a three-cat household it's genuinely worth the price. The globe design is large enough that it's harder for one cat to monopolise, it cycles within minutes of use so the box is nearly always clean when the next cat approaches — which is exactly what reduces territorial guarding around litter boxes — and it has a good app so you can track which cat is using it and how often, which is useful for spotting if your 2-year-old is still avoiding it. It takes standard clumping litter, the waste drawer is big enough that you're emptying it every 10–14 days with three cats, and the 8-year-old's reluctance risk is manageable — the cycling noise is fairly quiet compared to older models. It's around £450–£500 on Amazon UK. I'd buy one, put it in the new separate location, and keep a standard box as backup while everyone adjusts. Don't retire the old boxes immediately — let the cats choose on their own terms for the first few weeks.

Honestly, some older cats take to it immediately and some take two to three weeks — there's no way to guarantee it. The best approach is to put it in place with the cycle turned off for the first few days so she can explore it as a normal box, then gradually turn cycling on. Keep her existing box available and don't remove it until you've seen her use the Litter-Robot at least a dozen times without hesitation. If after four weeks she's still refusing it entirely, that tells you something about her specifically. But in my experience, reluctance is usually about the unexpected movement, and letting her investigate at her own pace before the mechanism starts solves it most of the time.

Exactly that. Separate locations first — that's free and may stop the floor accidents on its own within days. Then add the Litter-Robot 4 as the primary box in the new location, introduce it with cycling off, and keep an existing box running as backup until all three are comfortable. You probably won't need three self-cleaning boxes — one Litter-Robot plus one or two standard boxes spread across different rooms is the right setup for three cats and is well within your budget.