Hi HogHomeNormandie
Sounds like a thumbs up for your hog house from the hog! Yes, it does sound like nesting behaviour. It might be for a short stay, but possibly for a longer one. Sometimes hogs take in a small amount of material and only stay for a day or two.
If you are able to make another hog box, I would use that for the food and let the hog continue to build it’s nest in the original food box, if that’s what it seems inclined to do. Hogs seem to like keeping us guessing and not doing what we expect them to do! Something similar has happened to me in the past – the hog built a nest in the feed box and another feed box was required! If you choose to do that, don’t put anything which could be seen as nesting material into the new feeding box – you don’t want to give any other hogs ideas!
You could try to encourage the hog to move boxes, by doing as you suggested, but it might not work and the hog might prefer the original.