Am beginning to accept that he could be bored. But Sherman, most dogs will be alone from 11pm to 8am in any household, while owners are asleep and most dogs do not tear up lawns etc. Our dog is also alone from 9 to 5, I leave at 9 my wife returns at 5, and there has never been digging during the daytime, only at night. While we are at home he comes into the house, if he is dry, and gets lots of attention, walks, bike rides,talking to, play& fetch etc. We have no luck with having kids thus he has become the baby.
What i seem to need is some thing to occupy him at night rather than during the 'unfair' period in the day. Any dog cannot expect more than 12 - 16 hours interaction of whatever quality. Ours gets 6-7 of good quality. I dont think not being there is unfair to the dog. I accept it may be unfair to expect he will not find something to do (ie digging) and if that is the problem I will fix it as suggested if a digging area comes up short.
Moneygrower, some have good intelligence when directed at working sheep, this has been bred into them. I cannot accept that they are generally as intelligent as 11 year olds and ours failed to show any interest in working sheep for an experienced sheepdog trainer (and neighbouring farmer) and has failed to show more than average 'doggy' intelligence in any respect for us. We love him to bits but must describe him accurately for you.