Phantom litter box

[powerwoman]

So, just some background information: my ferret is a ~ 2yo male, very well-behaved for the most part, who was already (mostly) potty trained when I adopted him (just over a year back).

He has free range of my room, and most of the time is good about using the litter box. However, he seems to have chosen a random spot next to the door to go to the bathroom about 10% of the time, for whatever reason. I've seen him try this even when his litter box is totally clean, and even when he's closer to the litter box. This happens both when we're living in the dorm (he goes by the door), and living at home (goes under my desk). Wherever we are, he seems have made up one specific spot that- in addition to the litter box- he's allowed to go.

I've been moving him to the litter box when I see him start to squat, and praising him for going in the litter box, but otherwise I'm not quite sure how to approach this. Has anyone had the same issue, or have any additional litter box training tips they found helpful? I was lucky enough to get him potty-trained, so while I do have some experience training other animals, I'm sort of flying blind here. Thanks, I appreciate it!

[Heather]

You're doing what you can. This is territorial, he's not doing this to spite you. Ferrets will often poop right inside/in front of a door. You can try putting a litter box near the door (beside) and see if that will appease his sense of territory but that's what that's all about
ciao

[Charlie]

Mine has done this too, and goes by the door when he's out free roaming.