The Norwich Terrier is a breed of dog originating in the United Kingdom, and was bred to hunt small rodents. With a friendly personality, Norwich Terriers are today mostly a companion dog breed. One of the smallest terriers, these dogs are generally healthy, but are relatively rare, due in part to their low litter size and the common need for caesarian sections. Their drop-eared variety is the Norfolk Terrier. Description Appearance These terriers are one of the smallest working terriers (; at the withers), with prick ears and a double coat, which come in red, tan, wheaten, black and tan, and grizzle. Norwich Terriers can enjoy a tail length ranging from 2 inches to an impressive 8 inches. The consistency and frequency of tail wagging by the Norwich Terrier serves as an indicator of happiness. Temperament These small but hardy dogs are typically courageous, intelligent and affectionate. They can be assertive, but it is unusual for them to be aggressive. They are energetic and thrive on an active life. They are known to be consistently hungry and will eat anything edible. They are eager to please, but have definite minds of their own. They can be very sensitive to scolding. They should not be kept outside alone or in a kennel setting as they enjoy the companionship of their owners. Norwich are not known to bark unnecessarily, but will warn if a stranger is approaching. Once they realize that there is no threat, they become quite friendly. Norwich are generally good with children, and if introduced to other household pets as a puppy they generally co-habit peacefully, though caution should be observed around rodent pets as they may be mistaken for prey. Health US and UK breed surveys put the life expectancy of the Norwich Terrier at 13–13.5 years. While the Norwich Terrier is considered a healthy breed, there are some health issues for which responsible breeders do preventive genetic health testing, thereby reducing the incidences. The Norwich Terrier does have a predisposition for some health issues but studies to determine the exact mode of inheritance or the exact frequency in the breed are unknown or have not been conclusive. At present there are no disorders identified as "most important". Of secondary magnitude, cataracts are recognized as a disorder that has been reported sporadically and may be inherited. Also of a secondary magnitude there are instances of epilepsy, narrow tracheas,