Many Shelties grin, just like a person would. Many will bare their teeth while grinning. Though it may look similar, don’t mistake a grin for an aggressive curling of the upper lip. The situation should be an indicator of whether your Sheltie is grinning or snarling. Some Shelties talk to their owners in whines, grunts, groans, and even quiet growls, especially when being petted. Again, assess the situation. If your Sheltie is relaxed, it is most likely talking to you, not being aggressive. Since Shelties were originally herding dogs, many still exhibit behaviors such as biting and barking at moving objects (feet, brooms, vacuum cleaners, etc.) Your Sheltie may also chase moving objects such as other animals, people, or cars. Obviously, chasing cars can be fatal, so don’t allow your Sheltie to do this. Your Sheltie may even have a sense of humor. Watch for little practical jokes your Sheltie may play. You probably won’t believe this one until it happens to you.