Terrier dog breeds are energetic, alert, and confident dogs originally developed to hunt pests like rats and foxes, so they tend to be bold and curious even in a family home. Most terriers are small to medium in size with wiry or dense coats, and they usually need regular grooming plus daily exercise to stay happy and healthy. Their strong personalities mean they benefit from early training and socialisation, and for the right owner they make fun, loyal companions who love activities, games, and mental challenges.