Digging
Despite being considered a problem behavior by many owners, digging is actually a very normal and natural dog behavior.
WHY DOGS DIG
it's fun and great exercise
to stay cool/warm
to bury something
dig something up
some dogs are genetically driven to dig
it's a learned behavior
WHAT TO DO
Rather than trying to suppress your dog's natural instincts and take away a fun and relatively harmless activity, simply redirect her to a more appropriate digging area. You can give your dog a designated digging area, where they're allowed and encouraged to dig, so she's not digging holes all over your yard.
Once you've created or designated a digging area, put your dog inside and just barely bury a really big, super yummy treat - like a marrow bone or pig ear. You can even leave a little bit sticking out of the dirt. You want your dog to find it relatively easily. Every day for 2 weeks, go outside and bury a goodie for your dog. This teaches your dog that treats magically appear in that spot and nowhere else, which will encourage them to dig there. After the 2 weeks, periodically go out and lightly bury some treats for your dog to find. You'll also want to go out and fill their holes back in so they can continue digging there.
If you catch your dog digging in a spot they aren't supposed to, simply tell them, "Uh-uh!" and walk them over to their digging area.
HELPFUL TIPS
try to make the digging area a place they like to dig or already dig in
supervise your dog outside until they're no longer digging outside their area
make sure your dog gets enough exercise