Dr. Horwitz, a Veterinarian says:
It is quite normal for a young dog to investigate their environment and chew on items as part of that process. It is important to provide plenty of appropriate chew toys to avoid damage to household items and to prevent the puppy from ingesting dangerous items. When the puppy cannot be supervised, she should be placed in a safe, dog proofed area. Proper chew toys should be provided. These can be hard rubber toys that have been stuffed with food to make them more attractive. In some situations a puppy might enjoy manipulating feeder toy to get their meal. Rotating toys and providing different ones daily can help direct normal puppy chewing to the right place.