Clumping litter binds into a solid mass on contact with moisture, so waste lifts out whole and the rest of the tray stays in use. That means less frequent full changes and less litter thrown away. Non-clumping absorbs instead, and needs emptying completely more often.

Getting the depth right

Most litter problems come down to depth. Aim for seven to ten centimetres — clumping litter needs that much to form a clump that survives scooping, and cats need it to bury properly. A thin layer is the usual reason clumps crumble.

Tray placement and count

The rule of thumb is one tray per cat plus one spare, placed somewhere quiet and away from food and water. Cats will refuse a tray that feels exposed or that smells strongly of cleaning chemicals.

Scoop daily. If a previously reliable cat starts going outside the tray, treat it as a possible medical sign — urinary problems are common and painful — and speak to a vet rather than assuming it is behavioural.