The dog is digging to entertain itself due to being alone and
not have anyone to play with; it might need your attention.
A puppy under 3 years of age needs to burn up its energy.
If the dog sees you working in the garden, he/she also wants to join in.
(Some dogs just copy what they see their owner doing).
Dogs digging under a fence is because they want to get out to search for a mate.
Dogs like to dig in freshly turned dirt and fertilizer.
The dog likes to dig itself a den to cool off in warm weather.
Some breeds are very prone to digging like Labradors, Terriers and some others.
Some like to hunt for critters in the yard.
Some like to bury their bones.
Be very consistent.
Walk your dog 2 times a day to help burn up its energy.
Go to a dog park that will help the dog burn up energy.
Place your dog in a crate when you aren't around to watch him.
Spray the dog with the hose each time he digs. Be sure you do
this each time he is digging holes.
Add dog poop in the holes the dog has created.
Most dogs are really put off by this and won't attempt to dig again.
When you go away, leave a few tasty chew toys.
If you can give your dog a digging area, like a sandbox, fill it with soft sand and
bury your dog's favorite treats in it causing your dog to go there when it wants do dig.
Video on Digging:
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