Hi MerryMouse!
It’s perfectly normal for hogs to only stay a few days, and no you don’t need to change the bedding- they will bring fresh bedding if they want it, although it can’t hurt to leave some nearby for them. They usually prefer to take it in themselves, as you’ve seen.
It’s actually only advisable to thoroughly clean the hog houses a couple of times a year, in certain months, to avoid the risk of disturbing hogs that are hibernating or mothers with young.
It’s great that the house got used so quickly and I’m sure they will use it again. If you can make more houses I’m sure they would also get used, maybe even for hibernation. I have two hedgehogs that seem to sleep in my garden every day, but once a week or so they will switch to a different hog house. So I’m hopeful that some of them may be hibernating with me, although they have shown very little interest in nest-building so far.
