Claim: Major cities harbor rodent populations equivalent to one rat per person.
Example: [Washington Post, 2002]
Origins: Rats (at least the kinds commonly kept as pets) are for the most part intelligent, clean, quiet, sociable, and even affectionate. Still, there are many people who are absolutely repulsed at the sight of any rat and will run screaming even from the tamest Rattus norvegicus. This reaction is due in large part to our culture's association of rats with filth, poverty, disease, and death. Rats are the furtive invaders who hide in the dark, dank spaces of our buildings and towns, emerging en masse after dark to feed on garbage and food scraps. They can carry disease, either directly or via the insects that feed on them (such as the fleas whose bite spread the bubonic plague). Although in the wild they're shy and prefer to avoid contact with humans, they have long, narrow teeth housed in strong jaws that can deliver powerful defensive bites when necessary.
Rats tend to live where humans live, since the presence of man generally creates an abundance of food and shelter. Because rats live for the most part out of the sight of people and usually emerge from their dwelling places when we're either asleep or not around to see them, it's easy to imagine that far more of them are lurking in those impenetrable dark spaces than really are there. We create maxims that are far more reflections of our anxieties and fears about feeling surrounded by unseen crawly things than they are accurate estimators of
Another statistic in this vein is the "one rat per person"
The "one rat per person" claim stems from a study of rats conducted in England by W.R. Boelter and published in 1909 under the title The Rat Problem. Boelter surveyed the English countryside (but not villages, towns, or cities) and came up with an educated guess, estimating that England had one rat per acre of cultivated land. Since England had
But Boelter's estimate may have been way off the mark, and even if it was accurate, the putative 1:1 ratio between people and rats derived from it was merely coincidental, an artifact of England's just happening to have a human population equal to its number of cultivated acres. "One rat per person" was a figure unique to the time and place in which Boelter conducted his study, not a generalized figure that could be applied everywhere. Nonetheless, as Sullivan noted, "People loved that statistic, maybe because they abhorred it," and the figure is still frequently cited in news articles dealing with rat control efforts in large metropolitan areas, particularly New York City:
He added that there are about eight million rats living in the five boroughs. "That's about one rat per person," he said.2
City health officials believe there are several times as many rats in New York City as people
"There's no official rat census," says Pamela Miller, a deputy city health commissioner. "The estimates are anywhere from one rat per person to
Rattus norvegicus (University of Michigan)
Last updated: 5 September 2014
3. Curry, George E. "Rats Outnumber Residents in N.Y." The Toronto Star. 26 October 1991 (p. G9). 2. Jacobs, Andrew. "The Invasion of the Highway Rats, a True Story." The New York Times. 21 July 1996 (p. M13). 1. Jenkins, Chris L. "In Suburban Arlington, An Urban Bane: Rats." The Washington Post. 23 November 2002 (p. B1). 4. Sullivan, Robert. Rats. New York: Bloomsbury, 2004. ISBN 1-58234-385-3 (pp. 18-20).