Rat Film opens at the Roxie Theater in San Francisco on Friday

According to the creation legend cited at the beginning of Rat Movie (opening at San Francisco’s Roxie Theater on Friday, Oct. 27 — no East Bay play dates are currently scheduled), rats have been with us since time began, or perhaps even before: if this particular legend is to be believed, the humble rat helped bring the world into existence by gnawing a hole in Earth’s eggshell.

Rats seem perfectly designed for co-habitation with humankind, so perhaps it isn’t surprising that they’ve been given a measure of responsibility for our planet’s existence. Stable, predictable, and most importantly blessed with dietary needs quite similar to our own, the Norwegian rat (also known as the brown or common rat) now inhabits – dominates? – cities around the world, living comfortably off the waste and detritus of modern civilization.

Written and directed by Theo Anthony (who will be attending screenings on Saturday, Oct. 28 and Sunday, Oct. 29), Rat Movie gives us a glimpse of rattus norvegicus as experienced by the residents of Baltimore, Maryland. It also brings us up to speed on the sociological history of Charm City – one of the first cities to institute the practice that would become known as ‘redlining’, the blunt instrument of segregation that began life as a tool defining the relative desirability of various city neighborhoods.

Baltimore resident Edmond works as an exterminator for the city. Early in Rat Film, he suggests that there “ain’t never been a rat problem in Baltimore. Always been a people problem. And that ain’t gonna change until you educate the people.”

Anthony’s film is clearly intended as part of that education. Baltimore, it turns out, was the very first city to institute legal segregation via a 1911 law overturned in 1917 by the Supreme Court. That decision paved the way for private sector neighborhood covenants preventing the sale of houses to African-Americans and other minorities.

The history of Baltimore and the rat became truly intertwined during the early years of World War II, when a Rockefeller Foundation report raised fears of Nazi biological warfare spread by rodents. Until then, the only effective rat poison had been derived from a plant grown in the (now occupied) Greek Islands; Johns Hopkins researcher Dr. Curt Richter developed a deadly new toxin in the University’s Psychobiological Laboratory.

You can probably guess where the field trials for this substance took place. Richter asserted that his invention was suitable for widespread use and that it would cause nothing worse than vomiting in humans exposed to large doses; because his formula was considered proprietary, no government safety inspections were ever conducted.

Rat Film ties together these threads jarringly but effectively. Maureen Jones’ narration is as soft and dispassionate as a computer-generated voice; in contrast, electronic musician Dan Deacon’s frequently discordant score lends the proceedings a suitably disquieting air.

The end result is a documentary that, while occasionally overreaching (I’m not sure what its occasional computer-game graphics were intended to prove), effectively blends history, sociology and zoology into a coherent whole. But beware: there are some unpleasant rat death scenes, including a long, lingering shot of a pinkie being consumed by a snake. Proceed accordingly.

Freelancer John Seal is Berkeleyside’s film critic. A movie connoisseur with a penchant for natty hats who lives in Oakland, John writes a weekly film recommendation column at Box...