The most common reason for a dog to steal is that the dog wants more attention from its owner. If your dog is stealing items from around the house, you should always take those item back from the dog, otherwise the dog will believe that it is in control and can take whatever it wants. In most cases it is the human/owner who is solely responsible for the dog’s stealing.
What do we do when our dog has taught itself to steal?
Find several objects that may interest the dog. Get the dog on a lead. When the dog has picked an object and is making its escape, follow it calmly without making eye contact or saying anything. Using the lead pull the dog towards yourself and still without making eye contact and saying anything take the object from the dog and put it back in the place from which it was taken. This process should be repeated until the dog is bored. If the dog makes progress try this exercise without the lead, and every time the dog steals,repeat this exercise.