Live in this city long enough and chances are good you'll have a rat story to tell. Robert Sullivan has collected enough to write a book.

		Sullivan, author of "Rats: Observations on the History & Habitat of the City's Most Unwanted Inhabitants," spent one year observing rats in Eden's Alley, a little-used but garbage- rich alley linking Fulton and Gold streets. The book has more than 200 pages devoted to the author's study of the New York City rat, Rattus norvegicus, aka the Norway or brown rat. It details the history of the city's relationship with the rat, exposes the myth of "one-rat-per-person ratio" and offers a glimpse into the life of city rats, from their nightly scavenging to their voracious mating habits (20 times a day, in some cases). "Most likely, if you are in New York while you are reading this sentence … then you are in proximity of two or more rats having sex," Sullivan writes. He knows that the book's subject matter and details make some people squeamish.
"I'm going to read two chapters and then we can get on with the rat-free portion of our evening," Sullivan said at a reading on April 12 at the South Street Seaport Museum. "I promise." He needn't have rushed. Before the reading, some of the more than 50 audience members, whispered their own rat stories to one another. "I've seen them in capes-super-rats, the size of pit bulls," quipped Rick Simeone, director of operations for pest control at the city's Department of Health. During a question and answer session, Sullivan was happy to deflate the myth that some rats come in large-animal sizes. "It's not in the rat's best interest to be the size of a dog. The rat would need a bigger hole. He'd need a dog-sized hole." Sullivan claims no special affinity for rats, even the ones he studied in Eden's Alley. Most have since been exterminated. "The rats are gone," he said. "But you know they'll be back. They have a sense of history." Sullivan spent 100 nights in 2001 watching the rats in the alley, a walled-in lane he describes as being like his Walden. "Though, I'm not so nuts as to want to actually sleep there or anything," he writes. The alley, which snakes behind a Chinese food restaurant and Irish pub, was home to a colony of what Sullivan estimates were at least two dozen rats. With binoculars and night vision gear, Sullivan spied on the rats from each end of the alley, but over time grew comfortable enough to venture in among his subjects and peer into their nests. "Like the birder that returns over and over to the same woods, I grew comfortable in Eden's Alley," Sullivan writes. The book traces the city rat back to its first landing in the New World. "Most reports state that the very first Rattus norvegicus arrived in America in the first year of the Revolution, then moved out into the country, a manifest infestation," Sullivan writes. "One of their first landings was most likely New York City." Among the early rat tales Sullivan offers tells of rat fights, a popular pasttime among the rough crowd that lived near the seaport in pre-colonial days. He also offers a more realistic accounting of the city's rat population, pegging it at about 250,000. "Most of the rat stories you hear are crap," the Health Department's Simeone said. "But from what I've heard, it sounds like he knows his stuff."