They are what you call ,,,,,,,,sulkers,,,,,,,,,,Sulking at the edge of burrow ,,,,its in the breeding ,some guys just breed off any old ferret If a ferret has any faults ,just like the one you have ,don't put her in kit .I had a ferret with the same problem myself ........yes it would spoil the day out I gave her away as a pet to a young lad ?All I can say is buy another ferret from good breeder with good stock leave that Sulker at home.Trial and error ,,,all part of the game.....Happy Hunting