Hi PeterAlice
You did the right thing closing the lid quietly, so don’t worry. I would just leave it alone.
Sometimes a hog will settle down for the day in a feeding box and sometimes stay for a couple of days and then move one. It has happened several times here. Sometimes they will take in a minimal amount of ‘bedding’ – more of a ‘carpet’ really!
If you don’t see any sign of any more substantial nest building (which might indicate a female planning on using it for a birthing nest) you might be able to recommence using it for feeding again after a few days. I would open the lid very carefully in case the hog has taken up more permanent residence. But if, for instance, you see a trail of grass or vegetation going in, I would leave it alone.
I’m guessing you haven’t got a night camera? If you have you could aim it at the box to see what comings or goings there may be.
