No one can say with certainty exactly when the brown rat first came to America from Europe, but almost everyone agrees that it was sometime early in the American Revolution and that the rats’ first landing place was likely New York City. Even if, like the animals in Noah’s Ark, only one male and one female rat boarded a ship in England, they and their descendants could have numbered in the dozens by the end of a four-month transatlantic crossing and, under ideal conditions, 15,000 by the end of a calendar year. Rats are randy, having sex as many as 20 times a day. They have about six litters a year, and each litter includes an average of eight to 10 but sometimes as many as 20 rat babies, which will live for about two years.
Rats quickly became woven into the infrastructure of the city. Rats are tunnel-shaped for a reason: They are born to burrow. Sewage pipes, electric pipes, broken laterals from the earliest days of indoor plumbing provide the perfect habitat. “We have built, down below our feet, coming right out of our houses, all these rat apartment buildings,” Corrigan told me. “But we can’t see ’em and nobody pays attention to ’em.”
The transformation from urban menace to public enemy took place in the 19th century. The first rat attack I could find on record took place in 1860, when a baby was eaten in Bellevue Hospital. Her mother, an Irish serving girl, gave birth unattended in the night, and the child may already have been dead; the mother remembered “a cat or rat on the bed, but could not tell which.” The women’s wing of the hospital, a reporter for The New York Times explained, was built on land reclaimed from the marshes of the East River, on top of rock and rubbish and sewers, “and by these sewers the vile, gregarious, amphibious and nomade vermin, swimming in crowds from place to place, have been induced to stop.” In the female wards, the reporter wrote, “the rats in the night-time run about in swarms … This sounds like fiction, but we are assured that it is true. Myriads swarm at the water side after nightfall, crawl through the sewers and enter the houses. In a bath-tub, last Monday night, forty rats were caught.”
After 1893, when electric trolleys replaced horse-drawn ones, rats had to leave the stables where they’d snacked on grain and turned more often toward human residences. They eventually flocked to Rikers Island, which the city had begun using as a dump in 1894. Later, a prison farm opened on the island. Rats devoured the prison farm’s vegetables, pigs, and other livestock. At one time, more than 1 million rats were estimated to be living on the island. By the 1930s, the rats had begun to swim to other parts of New York, including the suburbs of Long Island, and serious exterminating measures were finally undertaken.