While a daily walk is essential to give your dog his fill of physical exercise, mental exercise is just as important. This is especially true for highly intelligent breeds like the Standard Poodle, the Border Collie, and the German Shepherd Dog. If you don’t give your dog enough mental stimulation, he will be more likely to become bored and develop problem behaviors like chewing or digging. If you’re looking to get your dog thinking, we have a few brain-teasing exercises to try. (Photo credit: underworld1/Bigstock.com)