In honor of my first full day as the only valet of the asylum, the boys very carefully showed me they knew which bathroom that their litter box was moved to. Unfortunately this didn't show me that they actually know where the litter box itself is, as the sign they left was a solid mess on the bathmat. I don't know if it was a hairball or something from the other end. I do know the bathmat immediately went in the washer. No other damage was noted.