You Need to Pay Attention
Some dogs will become very attached to their owners. This means that they need all the attention possible.
They may begin to chew if they do not feel satisfied, in order to get your attention.
Boredom
Dogs of all ages can be bored and chew on things. You can leave your dog alone too long and they will find things to chew.
When your dog is bored, he may also dig in the yard or chase smaller animals.
