The last time I dumped out the litter and did the deep clean was so funny. I was just finishing up and packing away the vacuum. Of course Tilly came right over and squatted to make her mark in one of the fresh boxes. Then Nutmeg came over, climbed into the SAME box as Tilly and squatted right next to her and peed right in the same spot! I have two very large boxes, but oh no - had to go in the same box as her sister. Thankfully no one was peed ON and it all ended up in the litterbox. Such silly kitties!