Rats: Observations on the History and Habitat of the City’s Most Unwanted Inhabitants

Robert Sullivan

Created on Friday, June 7, 2013.
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A wonderful, deep look at rats in the urban environment. I loved this book, and the reason there are so few excerpts for this one is because if I highlight all the bits that were interesting, they would typically run for 500 words each.


Rats have conquered every continent that humans have conquered, mostly with the humans’ aid, and the not-so-epic-seeming story of rats is close to one version of the epic story of man: when they arrive as immigrants to a newfound land, rats push out the creatures that have preceded them, multiply to such an extent as to stretch resources to the limit, consume their way toward faminea point at which they decline, until, once again, they are forced to fight, wander, or die. Rats live in man’s parallel universe, surviving on the effluvia of human society; they eat our garbage. I think of rats as our mirror species, reversed but similar, thriving or suffering in the very cities where we do the same.


It is sometimes erroneously stated that the rat gnaws solely to limit the length of its incisors, which would otherwise grow out of its head, but this is not the case: the incisors wear down naturally. In terms of hardness, the brown rat’s teeth are stronger than aluminum, copper, lead, and iron. They are comparable to steel. With the alligator-like structure of their jaws, rats can exert a biting pressure of up to seven thousand pounds per square inch.


Male and female rats may have sex twenty times a day, and a male rat will have sex with as many female rats as possibleaccording to one report, a dominant male rat may mate with up to twenty female rats in just six hours. (Male rats exiled from their nest by more aggressive male rats will also live in all-male rat colonies and have sex with the other male rats.) The gestation period for a pregnant female rat is twenty-one days, the average litter between eight to ten pups. And a female rat can become pregnant immediately after giving birth. If there is a healthy amount of garbage for the rats to eat, then a female rat will produce up to twelve litters of twenty rats each a year. One rat’s nest can turn into a rat colony of fifty rats in six months. One pair of rats has the potential of 15,000 descendants in a year.


Rats are thought to feel especially safe at corners, when they are simultaneously touching a wall and free to escape.


Throughout the 1950s, Davis was America’s rodent control guru. He traveled America’s rat populations. He consulted with cities on their rats, preaching his most important discovery throughout the countrythat poisoning rats was not in itself an effective way of controlling them. In fact, when rats are killed off, the pregnancy rates of the surviving rats double and the survivors rapidly gain weight. The rats that survive become stronger. “Actually, the removal merely made room for more rats,” Davis wrote. The only way to get rid of rats was to get rid of the rat food, or garbage, but no one wanted to hear this: as it was the dawn of the age of ecology so also it was the dawn of the age of the chemical, of poisons and pesticides, and people seemed to want a sexier, chemical-based fix.


Eventually, Davis became frustrated. He moved to Pennsylvania, where he studied animals other than rats. For a while, he studied woodchucks and once sent a colony of them on a boat to Australia in a darkened box to see how the trip to the other side of the world would affect their internal clock: on the ship, they stayed on Pennsylvania time, but when the box was opened in Australia, they switched immediately to Australian time.


Davis taught in North Carolina and then California, and in his retirement, he wrote a paper that applied his many years of animal ecology and population studies to human history; it was published by his daughters in 1995, a year after his death. In the paper, he posited that the great cathedrals of Europe were a result of an excess food supply for the human population at the time. To read this paper is to see that thinking about rats, as low-down as it seems, can easily lead to thoughts about larger topics, such as life and death and the nature of man. “The population trebled in three centuries,” Davis wrote. “As the population reached the capacity level of food and other resources, its growth stopped, and construction of cathedrals ended. The period terminated in wars, litigation, and disease. The hypothesis arose from the study of principles of population as derived from experiments on animals such as mice. Obviously, the test has not been experimental. A test that has many elements of an experiment is now possible in the oil-producing nations. These countries have suddenly found a source of energy. They will develop new types of art, literature, and science and will build vast structures not yet conceived. Then, as the population reaches the limit of resources (a complex stage involving the entire world), the period of history will end in stagnation, conflict, and misery. Humans have the knowledge to prevent a repetition of the later history of the Middle Ages.”


Here is this anecdote from an exterminator working in New York, in the borough of Queens: “A woman said to me, ‘Oh, we’re going to get a cat!’” he recalled. “I said, ‘Miss, please don’t put that cat in the cellar.’ Then I came back two weeks later and I’m picking up the hair and the bones of the cat. They think it’s like in the cartoons. But in the cartoons it’s Tom and Jerry the mouse, not Tom and Jerry the rat!”


After figuring out a place, after getting to know it intimately, killing rats is the easy part. “The textbook scenario, if you want to get rid of rats, is you put stress on their environment, you stop the food, and then they eat each other,” another exterminator told me.


an exterminator who was based in a Puerto Rican neighborhood in East Harlem told me that the rats there have learned to enjoy spicy garbage. This exterminator hypothesized that rats grow to enjoy the ethnic foods of the ethnic group in whose neighborhood they live. Post-Schein rat food studies corroborate this observation to some extent; this rat adaption is more technically described as a “local food dialect.”


To emphasize the deleterious effects of pigeon excrement to clients, he cites an incident a few years ago in which pigeon droppings cut through a cable on the Brooklyn Bridge, due to its acidity. The cable snapped and decapitated a man. “The object is to build out pests without pesticides,” he says. “That’s the future.” He foresees a day when he will be hired to analyze a building’s weaknesses, vis-a-vis pests and rodents. He sees this as a more humane pest control method, and humane systems are currently in vogue.


I’d spent some time on the telephone with a trap manufacturer discussing hypothetical rat trapping, trying to sound casual; I asked questions such as “If I was going to maybe have to trap rats, for example, what could I maybe use?” The saleswoman recommended chipmunk traps. Although I didn’t say so, I felt that the rats in my alley would not fit in a chipmunk trap, much less get trapped in one. I couldn’t decide if it was going to be easy to trap the rat and not necessitate buying a lot of stuff, or if it was even more difficult than I thought and I should buy a lot of stuff. In the catalog for Tomahawk animal traps, I found a lot of interesting trapping gear, such as Kevlar gloves, Kevlar sleeves, animal control poles, snake tongs and snake graspers, odor eliminators, Tomahawk Dura-Flex nets, telescoping syringe poles, dart guns, and even throw nets, all of which I could imagine being used in rat trapping. The goal would be twofold: (1) get the rat, and (2) stay the hell away from the rat.


Air infected by the venomous particles would become bad or miasmatici.e., poisonous. The venomous atoms were considered sticky and to be avoided. People avoided foul airs by holding flowers to their nose or dousing themselves with perfumes, which were invented as a response to plague. Some people felt that if they doused themselves with an odor more foul than the bad air, then they would be safe. Thus, in addition to bathing in rose water, people bathed in urine or stood for a long time in latrines. To some extent, such preventative measures often worked, though often not in the manner intended. In Italy, for example, doctors took to wearing robes made of toile ciree, a finely woven linen coated with wax and fragrance. Along with the linen robe, the doctor wore a hood and a mask and a long beaklike apparatus that was designed to filter the air. It made the wearer look like a large, sinister bird. In 1657, a friar, Father Antero Maria da San Bona ventura, who treated plague victims at a pesthouse in Genoa, noted that all the plague robe did was protect him from fleas, which the friar described as legion. “I have to change my clothes frequently if I do not want to be devoured by the fleas, armies of which nest in my gown, nor do I have force enough to resist them, and I need great strength of mind to keep still at the altar,” he wrote.


Thanks to the paranoia of politicians and businessmen during the first plague epidemic, plague had already spread from San Francisco into the rodents of California and the surrounding states, where plague remains today: there are more rodents currently infected with the plague in North America than there were in Europe at the time of the Black Death, though the modern rodents infected (prairie dogs, for example) tend to live in areas less populated by humans, as opposed to the rodents infected at the time of the Black Death.


And let me make this next answer perfectly clear: I think rats are really, really gross, though through no fault of their own. I think it is our fault, actually. We humans are always looking for a species to despise, especially since we can and do act so despicably ourselves. We shake our heads as rats overpopulate, fight over limited food supplies, and then go to war until the population is killed down, but then we proceed to follow the same battle plan.

That's all there is, there isn't any more.
© Desi Quintans, 2002 – 2022.