As small pets go, guinea pigs -- also known as cavies -- are virtual giants. In fact, each of the 13 guinea pig breeds recognized by the American Cavy Breeders Association can weigh up to 3 pounds or 1,360 grams (that's a lot compared to a parakeet). They come in several colors and patterns, and can have short or long hair.
Best For: Children of any age; a great "starter" pet
Feeding: Commercial pellets, prairie hay, fresh vegetables and water; daily dose of vitamin C
Housing and Exercise: Guinea pigs need lots of exercise. Pet retailers sell portable enclosures in which your guinea pig can safely explore an indoor or outdoor environment. You can add pipes for your pet to run through or offer hiding places like small boxes. However, resist the urge to add an exercise wheel to its cage. That's because running in a wheel could cause injuries to your guinea pig's back or legs.
Good to know: Guinea pigs are actually from South America (not Guinea) and aren't pigs at all.