A word here about rats. This is one of the elementary evils that new housing is supposed to eliminate and the presence of old housing to perpetuate. But rats do not know that. Unless they are exterminated, when old rat-infested buildings are torn down, the rats simply move into the next inhabited area. [..]

Most cities have legal requirements that rats be exterminated in any building demolished; in New York, the going rate in 1960 for a lying certificate of extermination, paid by corrupt owners to corrupt exterminators, is $5. How public agencies, like the Housing Authority, evade the law I do not know, but to know that they do evade it one need only go look at the fearful rat festivals and exoduses at twilight from their sites in process of demolition.

New buildings do not get rid of rats. Only people get rid of rats. This can be done in old buildings about as easily as in new ones. Our building was overrun with rats – big ones – when we got it. It costs $48 a year to keep it thoroughly rid of them and all other vermin. A live man does it. The notion that buildings get rid of rats is worse than a delusion because it becomes an excuse for not exterminating rats. (“We are soon going to get rid of these rat-infested buildings.”)

We expect too much of new buildings, and too little of ourselves.

- Jane Jacobs, The Death and Life of Great American Cities