The reason why dogs are so good at digging holes is that when they used to hunt, except for birds and large beasts, they used to catch and eat animals hiding in holes, such as rabbits, foxes and moles.
In mountains, there are many animals that hide in burrows or dig tunnels in the ground and live in them. They used to be one of the most important food sources for dogs.
However, Shiba Inus sometimes want to dig holes for purposes other than hiding things, hiding themselves, and catching prey. This is hard for humans to understand, but sometimes they will keep digging holes for the only purpose of digging.
This is called displacement behavior.
For example, just as humans sometimes relieve stress in their social life by playing sports or enjoying a meal, dogs sometimes do the same thing when they are stressed out.
If you are troubled by your dog's digging, it may be better to look for the cause of the stress instead of just scolding the behavior.
The cause of stress for dogs can be unexpected. For example, an air freshener that smells good to humans may smell bad to dogs, and music that is pleasant to humans may feel like noise to dogs.
If you've been away from home a lot lately, your dog may be feeling lonely, and if you've been quarreling with your family, your dog may be feeling uncomfortable.
It would be better to create a comfortable environment for dogs.