The book's jacket states it "...dispels the myths and exposes the little-known facts" about rats, and it quotes one reviewer's opinion that the book is "Appallingly informative." As a biologist, what I found appalling was the amount of misinformation it contained. Perhaps it's a result of the author being a writer and not a scientist, or because a lot of the "facts" he conveys seem to have come from a few self-styled rat experts he met along the way: "Ben", the New York City exterminator; "Ryan", the Southern Ontario corn farmer; and "Ang", chief of a city sewer maintenance crew, who told the author that "he knows `everything you'd ever want to know about rats--and more'", to which the author adds, "I don't doubt him" (p. 150).
Inexplicably, in the first chapter's lengthy discussion of the biology of rats and their impacts on humans, there is no hint that there exist multiple species of rats worldwide; in fact, it's implied that the singular "rat" originated in the swampy jungles of southeast Asia [actually, the now-worldwide Norway rat, Rattus norvegicus, first appeared in what is now northern China and Mongolia] and simply adapted (p. 16) or mutated (p. 18) so as to be able to survive in diverse environments.
Factual errors about rats include the following: all female rats over 6 months of age are "almost certainly pregnant" (p. 17); rats "can swivel their ears and, by measuring and comparing differences in intensity, triangulate and accurately estimate the site of a sound's origin" (p. 20); "Wild rats can swim well enough to catch fish" (p. 22); distribution of the black rat (R. rattus; "roof rat" or "ship rat") is limited to "just a few colonies in the palm trees above Los Angeles and a few other warm-weather cities" (p. 54); transmission of rat-bite fever to humans is normally through contact with rat urine (p. 72) [actually, it is primarily through bites]; and, small rats can squeeze through a hole the size of a pencil (p. 190).
The most blatant error occurs in the author's retelling of how an endangered flightless duck, the Campbell Island teal, was saved from extinction in New Zealand, where Norway rats had nearly decimated the species. Langton writes that a "park ranger" captured two ducks in 1976: "These... appeared to be all that was left of the species. Both were female, but... one (later named Daisy...) was pregnant [and] ...eventually gave birth to a number of litters--twenty-four ducklings in all" (p. 136-7). In reality, biologists first re-discovered the remnant teal population (thought at the time to number 30-50 birds) in the mid-1970s, but none were captured to initiate captive breeding efforts until 1984. Success was not achieved until 1994, when a pair (then dubbed "Donald" and "Daisy") successfully nested. "Daisy" successfully raised 24 offspring, but ducks don't "give birth" to "litters", and there's no such thing as a "pregnant duck".
Other faulty statements or implications are: "a female rat can, under good conditions, have well over 100,000 babies in her lifetime" (book jacket) [actually, 60 pups per year for a maximum of 3 years is a generous estimate]; during the mid 14th century as plague swept through Europe, "streets were clogged with cholera-infected corpses..." (p. 27); regarding discovering the cause of plague, "modern scientific method managed to isolate the virus, the flea, and the rat" (p. 28) [oddly, on p. 61 the author correctly names plague's causative agent at "a rod-shaped bacterium known... as Yersinia pestis"]; while rats are growing in numbers and distribution in the face of human activity, "virtually every other non-domesticated animal is rapidly vanishing" (p. 29); "A mouse is a smaller and far less complex animal than a rat... it doesn't impact the lives of humans on nearly the same level" (p. 30); "the brown rat lives generally underground" (p. 42); a century ago, black rats [R. rattus] ranged all over the United States and into Canada (p. 54); in the U.S., brown rats [R. norvegicus] are considered... the second most dangerous carrier of hantavirus (p. 74); "Although dogs and cats can contract plague, there has never been a record of a human receiving plague from contact with either animal" (p. 85) [actually, in the western U.S. from 1977 to 1998, there were 23 cases of cat-associated human plague, of which 5 were fatal]; coyote-dog mixes are commonplace in areas where both animals exist (p. 102) [actually, they are rare].
While the book is certainly entertaining, a good portion of it should be considered fiction.