The need for dogs to eat grass is rather a mystery and there are various theories behind the habit. None of these theories have actually been proven, but there are one or two things you can try which may prevent your dog from indulging.
Tail wagging and tail chasing are often associated with fun and pleasure, but this is not always the case. Sometimes these actions may indicate a problem, so it is important to take other body language into account too.
Dogs spend a great deal of time sniffing, much to the annoyance of their owners at times. However, sniffing is very important to a dog and is its only way of finding out important information.
Dogs often seem to bark at "nothing." Their keen sense of hearing and genetic predisposition to bark at strange noises causes this often-annoying behavior.