I've owned dogs all my life and the rule has been a dog won't poop/pee where it sleeps unless there is an emergency or it is sick. Well, this mentality is starting to make me concerned for my noodle.

I've had him for a little over a month now and he will only poop and pee in his hot hide. It isn't like he wallows in his own filth either; he spends the day in his hot hide, does some exploring around the cage and into the cold hide during the night, but we always know when he has gone to the bathroom because we will find him in his cold hide or tucked behind some foliage during the day.

Is this normal? Why does he do his business in his favorite spot if it just drives him out until we clean it?