There's a more common problem than people's pet dogs digging up yards... squirrels! These "tree rats" dig up whatever and wherever they want. Last year I used a humane "live" trap and relocated 27 squirrels from my yard to a wooded area over a mile away -- but now many other squirrels are here.
Neighbors said I can't use moth balls to keep them away because the chemicals might go into a nearby bay. (Besides, it's too hard to aim the moth balls and hit the squirrels!)
Since dogs must be leashed, squirrels have no natural enemies around here. Other than getting an eagle, can you suggest any effective anti-squirrel methods?