Terriers are a group of dogs that has a well documented history and purpose and which includes a wide variety of dog breeds. These dogs were mostly developed in the British Isles to hunt and kill vermin, such as rats, foxes or any other game that could damage crops or wreak havoc on farms. These dogs were bred to be small and sturdy, so that they could follow their prey into dens and burrows. Once they gained in popularity, they were also used on hunts. Larger hunting dogs, usually hounds, would chase quarry that would often hide in small spaces or dens; the terriers would be released and they would "go to ground", or enter the small hiding places, to flush out the hunted animal.
Though these dogs are not large, they have a very tough, courageous personality. They are also extremely energetic, with some bordering on hyperactive; they never back down from a fight, no matter how much bigger their opponent is. These traits were great assets when they were hunting vermin and going to ground. Entering the den of a badger or a rat, for example, was an EXTREMELY dangerous task; the animals were fierce to begin with, but being cornered in a small space made them highly vicious. Terriers had to have the strength to take these critters on and the energy to endure a fight to the death EVERY TIME they entered a den or burrow.
Most terriers show this extremely energetic personality and it takes a firm hand to be the owner of one of these breeds. With proper breeding and training, however, any terrier can make a great pet, as most were originally kept as companions and even guardians of children; they have a well-balanced temperament and are very friendly and willing to please. The Welsh Terrier is no different and has all the terrier characteristics wrapped into one wire-coated bundle. Indeed, it is a breed that is full of energy and doesn't tire easily. If you keep him pent up in the house, things may get destroyed; letting him chase something in the yard, maybe your 5-year old or your little brother, will give him the opportunity get rid of some of that energy and will make for a much calmer house dog.
Even though they display the typical terrier energy, Welshies are one of the quieter terrier breeds and are good companions even for an older couple that stays relatively active. Their terrier persistence and highly developed intelligence means that they are often concocting ways to entertain themselves, sometimes to the detriment of objects in the house; they should be stimulated mentally and physically on a regular basis to avoid behavioral problems. They can be left alone for some time, but make sure you give them a good amount of exercise everyday when you are home.