My second apartment in Baltimore was two blocks away from the first one. Then in a fit of uncharacteristic wanderlust, I bought a house that was two whole miles away. I lived there until moving three blocks to my current house.
Hopefully, that's where the rat in me ends. Glass, a professor at the Johns Hopkins Bloomberg School of Public Health, tells me a rat burrow basically has a pair, an alpha male and an alpha female, that goes about breeding the next generation. Given what the paper calls "high fecundity and generation overlap in Baltimore rats," the alley ends up as a community that is something like that song about a family filled with so many intermarriages that, as the narrator sings, "I'm My Own Grandpa."
More grossly interesting, or interestingly gross, facts about rat life: There's only room for one alpha pair per burrow, so eventually some rats leave home and create their own communities. They'll fight, "blood and skin," Glass says, over territories. But they generally stay close to their ancestral home - there can be four or five burrows in a single alley, he said. The study found that rats within an 11-block area were part of one extended family.
The Jones Falls serves as a natural barrier dividing east- and west-side rats. The differences between them are at the DNA level, but after years of studying them, Glass has noted that there are rats with black coats "and a beautiful white star on the chest" in one east-side neighborhood, around Jefferson Street above Orleans Street. "You go a couple blocks away, and they look normal again," he said, "mostly yucky-brown."
No doubt most urban rats behave like our own, but it is the Baltimore rodent that oddly enough is one of the most studied populations. Glass and others in the field frequently cite 1940s research on Baltimore rats that probably were the ancestors of our current vermin.
Rat scientists likely were drawn to Baltimore for the same reason Willie Sutton was drawn to robbing banks - it's where the rats are. As a result, our rats have developed a certain je ne sais quoi among rat researchers.
"People from New York are always asking me to send pieces of Baltimore rats to them," Glass said. "I think, 'You're in New York, you have your own rats.' "
Glass has a wry sense of humor, but it is unclear whether that is the cause or the effect of his choice of research subject. If you're interested in studying biodiversity within animal populations, he said, "one way to do it would be to go to the Serengeti and look at lions." He's pretty much to the opposite side of the spectrum, and as a result, Baltimore rats got their very own Boswell.
