Domestic and Wild Rat Species

Because there are so many species and subspecies of rats, it's hard to know where to begin. These animals have been around for centuries, growing, mutating and always adapting to new conditions. Rats have had relationships with humans for as long as we've shared the same space, resulting in disease, phobias and rat depictions in all forms of artistic media. However, a few rat originators are most familiar to and, in many ways, involved with human beings.

  1. Wild Rats

    • Rats in the wild are usually black or brown rats (also known as Norway rats). These "true" rats originated in Asia and came to Europe around the 1st century, hopping ships and opportunistically joining bands of roving humans to spread far and wide to the rest of the world. Brown rats, in particular, continue to live wherever there are people, eating their hosts' food (rats are omnivores) and making homes in the dark corners of all kinds of buildings. Highly social animals, these kinds of rats breed often, which can spawn even more deadly problems for the humans they follow: "Old World" rats and the fleas they carry are historically known to cause different varieties of plague, as well as other nasty bacterial infections and diseases like trichinosis, Q fever and toxoplasmosis.

    Pet Rats

    • Pet rats as we know them today descended from the brown rats snatched up by European rat catchers of the late 18th and early 19th centuries. During this period, rats were often sold for blood-related spectator sports like rat-baiting. Rat-baiting, which reached the height of its popularity in the early 20th century, involved releasing a number of rats into a pit and then counting down to see how long it would take a dog (usually a terrier) to kill the lot. Many catchers and game showmen began holding on to to their favorite rats -- usually animals that were particularly affectionate, intelligent or colorful -- and breeding and eventually selling them as pets. Rat appreciation societies began sprouting up across Western Europe and the eastern United States and the "hobby" of rat-keeping was born.

    Laboratory Rats

    • Lab rats became one of the early products of domesticated rat-keeping. Like pet rats, laboratory rats were often more docile than wilder varieties, which made them easy to handle in crowded research settings. In fact, most lab rats come from a group of brown rat descendants kept for biomedical research at the Wistar Institute of Philadelphia, Pennsylvania around 1906. Wistar rats are entirely albino and a better human counterpart to the house mice that, up until the turn of the century, were a mainstay of laboratory testing. Even now, upwards of 60 percent of all lab rats are descended from these white-headed, short-tailed rats.

    Rats as Food

    • In Europe, during times of famine, brown and even black rats were commonly caught and eaten by the starving poor. Today, rats around the world remain a part of many impoverished communities' staple diets. For example, the small, yellow-tannish rice-field rat (a cousin of the brown rat) is often consumed in parts of southeast Asia, usually skinned much like a rabbit and cooked over an open flame. The connection between the rice-field rat and the humans whose food it eats (largely rice and beans) thusly continues to illustrate the long-held, give-and-take nature of rat-to-person relationships.