Pet rats are almost all a domestic breed of the Norwegian Brown Rat (Rattus norvegicus). Some people call them fancy rats, which is a term derived from rat fanciers or people who fancy rats. There are other species of domesticated rats, such as the Gambian Pouch Rat, but the vast majority of pet rats are all the previously mentioned species.

Popular domestication of rats began in the late 19th century, when rat-catchers in England were paid to kill rats and began keeping some of them for fighting purposes. A notable rat-catcher, Jack Black, famously caught rats for Queen Victoria and began breeding and selling them. The first rat show was held in England in 1901 and helped spread the popularity of these pets. Several rat fancy organizations have since formed, including the National Mouse and Rat Club and National Fancy Rat Society.

Despite the popularity of pet rats, many people are disgusted by even the sight of a rat, yet adore "cuter" animals like hamsters and rabbits. This attitude towards rats likely stems from their reputation as a pest and carrier of disease. Indeed, throughout history, rats have infested grain supplies, homes, and even supplied plagues, leading to their demonization. However, the domestic rat is not deserving of this adversity, since it is bred for its social nature and of course domestic rats very rarely harbor diseases that affect humans.

Unlike their wild cousins, which typically display a simple brown or black fur coat, domestic rats are bred for unique colorations. The Berkshire style is colored except for a white belly. The hooded rat has color running from the head down the spine. The Capped style has color only on the head. The albino rat is popular and has brilliant white fur and reddish-pink eyes. A hairless rat morph is also available, as well as a popular dumbo morph with larger ears that are situated more on the side of the rat's head.

As a pet, the rat is very gentle and social as long as it has been acclimated to humans properly. It is a good idea to buy a pet rat from a breeder that handles the juvenile rats and makes them accustomed to humans. Rats obtained from pet store chains may be mishandled or even treated cruelly, resulting in a very timid or even aggressive personality. You can get an idea of a rat's personality by handling it before buying it. A well domesticated rat will not squeak or nip when picked up and will readily accept food from your hand. A poorly domesticated rat will often flee from humans when given the chance.

Unlike the popular Syrian Hamster, rats are very social animals. In the wild, rats are often found in groups that nest, travel, and groom together. Similarly, rats can safely be kept in cages with other rats. It is advised that you only keep rats from the same sex, since they are notoriously quick breeders. As long as they are well fed, rats typically do not fight, although they will often play and establish dominance. Rats are typically nocturnal and sleep during the day, so it is best to interact with them in the morning or evening, although they seem to have no problem waking up for a bit of play.

Rats are also fairly intelligent and some people have had success with potty training and teaching other tricks. Some have reported getting their rats to respond to their name. They are also curious animals that love to explore and getting toys to play with in their cage. I usually supply mine with toilet paper and paper towel tubes as well as small cardboard boxes and tissue paper to nest in.

Rats typically live up to three years, with the oldest recorded lifespan being seven years and four months. Males are slightly larger than females and females tend to be more active than males. It should also be noted that male rats exhibit marking behavior, where they frequently drop small amounts of urine to mark territory. This behavior can be limited by neutering males, but it is only a minor problem for most people.

Rats should be housed in a nice roomy wire cage so they can climb the walls and run about. An aquarium is NOT recommended since it provides poor ventilation and ammonia from urine will build up inside if it is not cleaned regularly. A good rat cage would have multiple stories for climbing and some people provide a wheel for their rats to run on, even though rats generally don't take to the wheel as avidly as hamsters. At a minimum, rats should be provided with a water bottle, unscented bedding, and rat food.

Rats do develop health problems on occasion. Older rats often develop benign tumors that can be removed by a vet. Some rats become afflicted with respiratory ailments that cause sneezing and sometimes death. If a rat is kept in low humidity or in an area with drafts it can develop a condition called ringtail.

Overall, domesticated rats are great pets that take well to captivity. They are arguably more social and friendly to humans than hamsters, guinea pigs, and gerbils. However, despite their reputation and low price, rats deserve respect from owners and should be given appropriate living conditions. With proper housing, bedding, food, and water, a rat will live a fulfilling life and enjoy spending time with its owner.