Millions of human beings have died because of Rats and Mice (jointly called Rats in this section). Rats eat huge amounts of grains and other foodstuffs worldwide each year, causing starvation to many people Worldwide, destroy dams, start fires and weaken structures. Rats also carry disease, such as typhus, spotted fever and tularemia. However, rats are infamous for causing the Black Death in the Middle Ages. Rats carry fleas which live on the blood of Rats, until the fleas jump off and bite humans. The most disastrous mass death toll of humans in the Middle Ages was caused by Bubonic Plague (This was called the Black Death), which was carried to humans by the fleas, which lived on the Rats, until they then bit humans, transmitting this deadly disease. Then humans spread the disease to others. The Black Death was credited, in five years, with the death of about 25,000,000 human beings, between 1347 and 1352.

From the website http://www.byu.edu/ipt/projects/middleages/LifeTimes/Plague.html,
we borrow the following information:
This article was created Dec 8 1994 by Aaron Rice (jar22@email.byu.edu)
a Timpview High School student, in partnership with the
David O. McKay School of Education, Brigham Young University

The Black Death: Bubonic Plague

In the early 1330s an outbreak of deadly Bubonic plague occurred in China. Plague mainly affects rodents, but fleas can transmit the disease to people. Once people are infected, they infect others very rapidly. Plague causes fever and a painful swelling of the lymph glands called buboes, which is how it gets its name. The disease also causes spots on the skin that are red at first and then turn black.

Since China was one of the busiest of the world's trading nations, it was only a matter of time before the outbreak of plague in China spread to western Asia and Europe. In October of 1347, several Italian merchant ships returned from a trip to the Black Sea, one of the key links in trade with China. When the ships docked in Sicily, many of those on board were already dying of plague. Within days the disease spread to the city and the surrounding countryside. An eyewitness tells what happened:

"Realizing what a deadly disaster had come to them, the people quickly drove the Italians from their city. But the disease remained, and soon death was everywhere. Fathers abandoned their sick sons. Lawyers refused to come and make out wills for the dying. Friars and nuns were left to care for the sick, and monasteries and convents were soon deserted, as they were stricken, too. Bodies were left in empty houses, and there was no one to give them a Christian burial."
The disease struck and killed people with terrible speed. The Italian writer Boccaccio said its victims often

"ate lunch with their friends and dinner with their ancestors in paradise."
By the following August, the plague had spread as far north as England, where people called it "The Black Death" because of the black spots it produced on the skin. A terrible killer was loose across Europe, and Medieval medicine had nothing to combat it.

In winter the disease seemed to disappear, but only because fleas--which were now helping to carry it from person to person--are dormant then. Each spring, the plague attacked again, killing new victims. After five years 25 million people were dead--one-third of Europe's people.

Even when the worst was over, smaller outbreaks continued, not just for years, but for centuries. The survivors lived in constant fear of the plague's return, and the disease did not disappear until the 1600s.

Medieval society never recovered from the results of the plague. So many people had died that there were serious labor shortages all over Europe. This led workers to demand higher wages, but landlords refused those demands. By the end of the 1300s peasant revolts broke out in England, France, Belgium and Italy.

The disease took its toll on the church as well. People throughout Christendom had prayed devoutly for deliverance from the plague. Why hadn't those prayers been answered? A new period of political turmoil and philosophical questioning lay ahead.


Estimated population of Europe from 1000 to 1352.
1000 38 million
1100 48 million
1200 59 million
1300 70 million
1347 75 million
1352 50 million
25 million people died in just under five years between 1347 and 1352.

For more accounts at this site see: (the article gives the following websites, which are not linked at this time to the Proctor Museum of Natural Science page here, but if you go to the website link above, you can then go to these links:

These are website links in the article cited above:
Black Death Spreads
The Plague: Will it Ever End?
I Saw the Death
The Medieval Miracles of Healing -- Medical Science

For more accounts at different sites see:

The Plague: an account from Boccaccio's The Decameron
Plague and Public Health in Renaissance Europe
The Plague - created by a Texas high school student
The Black Plague - graphic intensive and loads somewhat slowly, but contains excellent pictures and an interesting account.
Go to Middle Ages Main Page

Here are five views of the same rat--caught in a live trap,
drowned and then scanned for good uninjured viewing

Norway Rat
Rattus norvegicus
Brown Rat
top view
Norway Rat
Rattus norvegicus
Brown Rat
top view without
back lighting
Norway Rat
Rattus norvegicus
Brown Rat
bottom view

Norway Rat
Rattus norvegicus
Brown Rat
right side view
Norway Rat
Rattus norvegicus
Brown Rat
right side view

Norway Rat
Rattus norvegicus
Brown Rat

Here is some information on this rat which is common throughout the U.S., Southern Canada and much of Europe.

This is to express our appreciation to the eNature.com website, whose website is shown below-click on it to go that site:http://www.enature.com/fieldguide/showSpeciesFT.asp?fotogID=944&curPageNum=46&recnum=MA0095
This website material is copyrighted and is used on this Proctor Museum of Natural Science website under their "fair use" exclusion or consent "One exception to this policy is for text usage (NOT photo usage) that falls under the "fair use" policy of the U.S. Copyright Office. "Fair use" generally includes text reproduced for the following purposes: (and permissible uses include teaching and by various other noncommercial/nonprofit purposes. Therefore, be advised that copying this material is not permissible, without the written consent of the above website owner.

Description Brownish gray above; grayish below. Scaly tail slightly less than half total length, darker above than below. Small eyes. Prominent ears. L 12 3/8"–18 1/8" (316–460 mm); T 4 3/4–8 1/2" (122–215 mm); HF 1 1/8–1 3/4" (30–45mm); E 5/8 –1" (15–25 mm); Wt 6 7/8–17 oz (195–485 g).

Similar Species Black Rat has proportionally longer tail (more than half its total length). Woodrats have white underparts.

Breeding Breeds year-round; like other rodents, sometimes mates within hours of giving birth; gestation 21–26 days; female may bear up to 12 litters per year of 2–22 young (usually about 5 litters of 7–11 young). Young born hairless and blind; open eyes at 2 weeks; are weaned at 3–4 weeks.

Habitat Farms, cities, and many types of human dwellings; in summer, often cultivated fields.

Range Southern Canada and entire continental U.S.; Pacific Coast north to Alaska.

Discussion While early scientific descriptions of this species came from Norway, and it was once believed to have arrived in England in the 18th century aboard Norwegian ships, the Norway Rat is neither a native of Norway nor more common there than elsewhere. Probably originating in Central Asia, from the 16th to the 18th century it spread across Europe both overland and aboard trading vessels; it arrived in North America about 1776 in boxes of grain brought by the Hessian troops hired by Britain to fight the American colonists. The Norway Rat makes a network of interconnecting tunnels 2 to 3 inches (50–75 mm) across, up to 1 1/2 feet (450 mm) deep, and 6 feet (2 m) long. Such a network contains one or more chambers for nesting or feeding, one or more main entrances, and several escape exits. This rat digs by cutting roots with its incisors, freeing dirt, pushing it under its body with its forefeet and out behind with its hind feet, then turning around and continuing to push the dirt out with its head and forefeet. Its vocalizations include squeaks, whistles, and chirps. This loosely colonial rat is a good climber and swimmer. Omnivorous, it feeds on meat, insects, wild plants, seeds, and stored grain, contaminating with its droppings what it does not eat. It will kill chickens and eat their eggs. Food shortages and unfavorable climates sometimes limit this rat’s reproductive potential, resulting in fewer and smaller litters. When food is abundant, females may produce a dozen litters in a year. At two years, females stop breeding and males’ reproductive powers diminish. Snakes, owls, hawks, skunks, weasels, Minks, and dogs are predators. The life span is about three years, but few Norway Rats live that long. If local populations become severely overcrowded, mass migrations may occur. In 1727, hordes of Norway Rats were observed crossing the Volga River in Russia; though millions drowned, many survived. The German nursery legend about the Pied Piper of Hamelin, who rid the town of rats by musically charming them into the Weser River, where they drowned, probably grew from observations of rat migrations. Rats are a major carrier of diseases such as typhus, spotted fever, tularemia, and Bubonic plague, and their destructive powers are enormous. As well as eating grain and ruining property, rats have started fires by gnawing matches and caused floods by tunneling through dams. The white rats used in laboratories are specially bred albino strains of the Norway Rat.

NOTE: We have been advised, by a person raising rats that the rat shown is not a Brown rat, but rather a Black Rat, Rattus rattus. The information sent to the PMNS by this person states:

The photo you have on the page, claiming to be a brown or Norway rat is actually that of a black/ship rat, rattus rattus, despite the brown fur. Of course black rats can have brown fur. Just thought you should know.

The rat you have there is definitely a black rat, note the large ears, larger feet, the fur continuing onto the fore paws (they don't do that in brown rats). The tail is FAR too long to be a brown rat, and the nose far too pointed. The belly is white, often brown rats will have a slate grey belly, but hardly ever white, and not with such a clear line in between top and bottom colourings (apparently the email is from the United Kingdom as in the U.S. we spell it coloring (without the u). Continuing:

(then again this information is noted on the webpage, uh...) http://www.newpestsolutions.com/images/roof_rat.jpg
Here's a good image of an adult black rat, http://www.abc.net.au/wildwatch/gallery/intro_mammals/002_brownrat_l.jpg
And an adult brown rat, showing off the smaller ears, blunter head, bulkier body and thicker, shorter tail.
I can understand why there was a mix up, the animal shown is young and malnourished, but after experiencing brown rats at that age through breeding litters from my own pet rats, I can safely say the specimin (sic specimen) in question is not a brown rat. Thank you for your time.

We wish to thank the contributor, who is undoubtedly more expert on rats than is your PMNS Curator and we will yield to his determination. Thanks to a gentleman named Bob Hayley for these comments and information.