When we adopted Blackie, around age 8, we were told that he "occasionally" pooped outside the litterbox. Like your kitty, he would pee in the box, no problem, but sometimes he would leave a pile right outside the entrance to the box. As he got older, he did it more often until he was leaving a pile outside the entrance to the box almost every time We tried spraying Feliway, using Feliway dispensers, moving one box away from the others, putting in more litter or less litter, putting paper towels or aluminum foil outside the front of the box, changing the type of litter, cleaning the box as soon as he peed (when practical), and had him checked out at the vet several times, all to no avail. The weird part was he would stand and scratch around the pile as though he were covering it over. He never went anywhere else but right outside the entrance to the box. We never figured out why he did it or how to stop the habit. Blackie is at the Rainbow Bridge now after surviving years with diabetes and hyperthyroid, but I would gladly clean up his mess if he could be with us still. We miss him Good luck with finding a solution and please let us know what it is if you do!