High sides stop litter escaping over the walls during ordinary use, but a determined digger defeats them by physics rather than defiance: she digs with force directed backwards, and litter thrown from the bottom of a deep hole arcs over the rim on exactly the side she faces away from. Burying is instinctive covering behaviour, and many cats perform it with theatrical thoroughness long after the waste is buried. Before buying another tray, look at how she digs, which direction the scatter lands, and how much of the mess leaves on her paws rather than through the air, because each route out needs a different fix.
Read the scatter pattern before changing anything
Stand back and map the mess for a few days. A fan of litter spread behind one short end of the tray points to kick-back while digging. A trail of granules leading away from the entrance, fading across the room, is tracking on paw fur and pads — worse with longhaired cats and fine litter. A ring scattered evenly all around suggests the tray is simply too small, so she digs with her body half out and her paws throwing litter in every direction. Each pattern tells you whether to work on tray orientation, a catching surface, or tray size first, instead of replacing everything at once and never learning which change mattered.
Turn the tray so her digging works for you, not against you
Most cats adopt a preferred digging stance, often facing the same wall each visit. If that stance sends litter over the open side toward the room, rotate the tray a quarter or half turn so her kick-back lands against the highest wall or into a corner. Keep the entrance easy for her — she still needs a low, obvious way in, especially if she is older — but let the solid sides do the containing on the digging side. A tray placed in a corner or alcove gains two free walls of protection, provided the spot stays quiet and she never feels trapped there by other pets. Avoid covered trays as the first answer for a cat who already digs hard; some cats accept them, but others dislike the enclosed air enough to create a bigger problem than scattered litter.
Size and depth: the quiet causes of dramatic digging
A tray that is too short forces a cat to scratch at a steep angle close to the edge, which launches litter efficiently. She should be able to stand fully inside and turn around with room to spare; for many adult cats that means a tray noticeably longer than the cat herself. Depth cuts both ways: litter filled very deep gives her more material to excavate and throw, while litter that is too shallow frustrates burying and provokes harder digging to reach a satisfying depth. Aim for a middle depth she can dig a proper hole in, and top up little and often rather than refilling generously once a week, which keeps the level — and the throwing range — consistent.
Mats that actually catch litter, placed where litter lands
Choose a mat sized to the scatter, not just to the entrance. A dual-layer or deeply grooved mat extending well beyond the exit and digging sides traps granules kicked out and granules carried out on paws, and can be lifted and poured back or shaken outside in seconds. Smooth thin mats do little: litter skips across them at speed. Place the mat so its longest reach covers the fan direction you mapped, over hard flooring where strays are easy to sweep, rather than on carpet where granules lodge deep. A washable mat matters too, because a mat that smells of old litter will eventually be treated as part of the tray. Once you find the rotation, size, depth, and mat position that keep your floor clean, save that layout in KinsLe using Family Sharing so whoever washes the tray or moves it for cleaning restores the same arrangement instead of scattering your solution.