verb: to follow closely behind, or to check (someone) frequently, implies that the action causes some annoyance or interference (from the fact that a pet dog will often follow closely at its master'sheels).
A domesticated canine that comes in many different breeds. Due to dogs' ancestors growing accustomed to humans over time they have evolved to have bigger brains than other common pets such as cats.
Some dog breeds (such as German Shepherds and Border Collies) are very intelligent and are able to have jobs (such as sheep herding or more recently police work and rescue work).
