I just joined this site but with your 4 month old lab I have found that they can sometimes get what is called a dependency problem wich can lead to excessive barking one of the quickest and kindest ways to fix this is if you are going away for a couple of days put him in a boarding kennel for the time,JUST MAKE SURE THEY DO NOT TRANQUILISE DOGS, all will say they don"t but a lot will check if anyone here knows a good kennel on the coast, the other thing is the mouthing will stop just continue with what your doing he is teething at the moment with the digging if it is just the lawn and he keeps going back to the same spot put a blown up balloon in their when he digs it will pop give him a fright and should stop him if it is your garden more than likly it comes back to the dependancy problem as your smell is in your garden make sure you give him one spot to dig for cool dirt as they will do this on a hot day
