It all depends on what you call a hard terrier.Lads definition of hard vary.The dogs i keep most lads would say there hard,but i would say there hard workers,but with brains to match.Sounders are grand,but i seen a lot just when your about to break through the quarry will push and the dog move with it,which means a second hole to open.I also seen dogs which get a few marks on a dig and there owners think there in bits and lay them off for weeks,i give mine a week and there grand,but everyone to there own.