This crowd are the rodent-operators of the canine world, as their ancestors were bred to hunt and kill vermin. They vary in size from the Airedale, the tallest, down through to the Fox Terrier and the Lakeland Terrier, medium, to the West Highland White Terrier and Norwich Terrier, the shorter-legged varieties.

Terriers tend to have distinctive personalities, of being energetic, feisty and self-confident. They typically have little tolerance of other animals and dogs and need owners who are prepared to match their dogs' lively character. Many Terriers have wiry coats that need special grooming known as stripping (plucking out the dead hairs) to keep their sharp appearance. They are generally smart dogs and are all vocal to a degree. Terriers make excellent pets as they adapt extremely well to castle or cottage.