The importance of mental stimulation and enrichment for dogs can not be overstated. From work-to-eat toys, to chew toys and scent games, the options are almost endless.
Puzzle toys can keep a dog busy during meal time, a stuffed Kong can be used to keep a dog occupied while crated and kibble or treats tossed in the grass gives dogs a great opportunity to use their finely-tuned noses.
Dogs get into a good chew toy the way we get into a good book or movie. When we provide "legal" outlets for normal behaviors, those behaviors we humans see as problems are likely to decrease.