How the civilized world keeps rats at bay.

A cynic might say that New York City rats come in two varieties: two legged and four legged. Luckily, only one of those species chews through walls and electrical wires. New York is a city of 8 million people, and at least as many rats, and keeping destructive rodents away from sensitive equipment and populated areas isn't just a job for restaurants. Commercial businesses must also contend with pests, and as the City continues to grow, the job will be more and more difficult and important.

The species of rat that lives beneath New York City like a gang of quadrupedal straphangers is the Norwegian rat, or Rattus norvegicus. Contrary to popular belief, these rats do not spread disease. According to Dr. Robert Voss, Curator of Mammals at the American Museum of Natural History, there has never been a single instance of a pathogen being transferred from the Norwegian rat to humans.

"The Norwegian rat is no more dangerous than a squirrel," said Dr. Voss, "people simply don't like rats, unlike squirrels, which they find attractive because of their big eyes and bushy tails. The main difference is that rats are burrowing, terrestrial, animals, and squirrels are arboreal. So in cities, squirrels live in trees, and rats live in buildings."

The number of rats in New York City is unknown, and the estimates vary widely. The commonly quoted value of one rat per person is not based on hard data, and is probably an urban legend. A rat summit in 2002 estimated the ratio of rats to humans in New York City at approximately 12:1, or around 96 million rats. In 2000, Bill Perkins, then chairman of the City Council's Select Committee on Pest Control posited that there were 9 rats for every human, or about 70 million. In 2000, the City spent $13 million to combat the rat problem.

Like all rodents, rats need to continually chew on a hard surface to wear down their perpetually growing front teeth. In an urban setting, this leads rats to chew on whatever is around, be it concrete, wires, or walls. Over time, this can be terribly destructive. Edward Andron, vice president and director of management at Leebar Management Corp. has even seen rats chew on steel.

Andron has worked on numerous construction projects, both residential and commercial, and rats have proved omnipresent at all of them. "They usually come in during construction or renovation. I was working on a renovation project when the building next door came under construction, and my building got all the rats driven away by the construction next door, and we had a big problem," said Andron.

"In another office building I was working on, the rats seemed to be attracted to the accounting department. I think they kept the most snacks in their desks, and the food attracted the rats. Also, any commercial building with restaurants on the ground floor, no matter how clean, the restaurant ends up with rats." Seeing as nothing can fully stem the tide of rodent invasion, most business opt instead for methods that will mitigate rat infestation. Andron noted that not eating at one's desk, as well as the use of rat-proof garbage bags, can help minimize the level of rodent infestation. "The bags are double tough, and there's some kind of chemical in them that prevents the rats from being able to smell the garbage," added Andron.

Robert Bertuglia III is also no stranger to dealing with rats. Bertuglia is a director at LARO Systems Services, a major janitorial and cleaning company in the city A 30 year old company with 900 employees and $65 million a year in business, LARO has cleaned some of the toughest spots in New York City, including Kennedy and LaGuardia Airports, and the Port Authority Bus Terminal in Time Square.

Bertuglia observed that rats start appearing in days, if not hours, after construction begins on a site, and then they tend to stay.

"The first place we find them is in basements, garbage areas, and loading docks," said Bertuglia. He noted that the first step is disinfecting those areas, before the rats have a chance to spread to the rest of the building. This process is ultimately futile though, as rats learn to avoid traps and areas with pesticide.

According to Bertuglia, constant maintenance is the best method to minimize the impacts of rats on a commercial business. Regularly cleaning desks, changing garbage, and disinfecting the garbage cans themselves, are crucial to preventing a rat problem. Sadly, it is this routine maintenance that business owners tend to neglect. "Property managers don't realize the impact, quite honestly. They always look at cutting down on the cleaning service as one of the first places for cost saving, and there's a price to pay for that. You're increasing the chances of encountering the problem. We've been in some situations where there's significant damage, and we can't help anything. At that point, you need electricians, not exterminators," said Bertuglia.

However, in the end, the rat problem may be both overblown, and not a rat problem at all.

Stuart Bogard, owner and president of Pro-Tech Pest Control, has been working in the exterminator business for over 20 years, and says that less than half of one percent of his jobs involve rats. As Bogard sees it, rats aren't the problem at all.

"The biggest problem is the people. If you don't give a rat food, he won't come in there. If you don't give him a hole to get through, they won't come in. You can stop anything from coming into your building if you want to spend the money," said Bogard, adding, "Sometimes it's as simple as sealing the hole with a ten pound bag of cement."

Rattus norvegicus evolved in Asia thousands of years ago, just as civilization was beginning to take root. As soon as there were cities, humans had to share the space with rats. The last 5,000 years has seen a constant give and take between the rats, who want to live off of human production, and city dwellers looking to rid themselves of vermin.

Like it or not, by attempting to deal with rat problems, business in New York City are participating in a practice as old as civilization itself.