Hi MerryMouse
I would be inclined to clean the house out. If a hog has been using it for short stays it could easily have left some external parasites and their eggs, in payment! Just make absolutely certain there is no-one in residence before you begin. A rolled up ball of paper or leaf or twig – that sort of thing – in the doorway, might help you be sure. Then just open the lid very carefully just to be completely certain.
This is one of the times of year to clean out hog houses, anyway – before hibernation. The last thing you would want is for some poor hog to begin hibernation with loads of external parasites.
So I would dispose of the material the other hog used. Use gloves and make sure you don’t get any ticks on you and then use boiling water to kill any eggs that may have got into the cracks. Dry thoroughly and then just add a handful of material to give them idea and leave loads of material nearby. Medium sized leaves are preferred for building nests, especially hibernacula.
