The state says it’s the city’s problem. The city says it’s the state’s problem. And residents of Portland’s Libbytown neighborhood just want somebody – anybody – to deal with the rats that have swarmed in since brush was cleared recently from around a nearby highway exit. In fact, the state and the city cooperated in the brush-removal venture, so they should work together on a plan to contain and conquer the unwelcome aftermath.

The brush-clearing project was carried out late last year by the Maine Department of Transportation. Undergrowth was removed from alongside Interstate 295 and its Portland access ramps. And, at the city’s request, MDOT workers also dismantled homeless encampments there.

Explaining why the MDOT doesn’t plan to take any action against the rats, agency spokesman Ted Talbot said that the vermin live around the Fore River and what drew them to I-295 was the food consumed by the people living in the now-razed encampments.

“Now that that has gone,” he told the Press Herald last week, “it may be they’re still in the hunt for that type of stuff. But we didn’t increase the infestation by clearing out that shrubbery.”

But science doesn’t support this view. Rats tend to stay in one area, Tulane University scientist Michael Blum has found via his research in New Orleans, and they favor places with relatively few people but lots of undergrowth.

Taking away the brush where rodents like to live will send them elsewhere. This jibes with the observations of a Libbytown resident who believes the rodents that she’s been seeing fled into her part of the neighborhood when a heavily wooded buffer near Huntress Street was cleared.

The infestation could have been predicted and a de-escalation program planned before the clearing project began. But that didn’t happen – so now the MDOT should be held accountable for the results of the brush removal.

And since part of the endeavor was undertaken at the request of the city, it would be in Portland’s best interest to cooperate in driving out the rats.

New Orleans has had success by promoting “integrated pest management,” addressing conditions that pave the way for rats: closing the holes that allow rats to get into buildings; keeping the shrubbery pruned; using metal trash cans with tight-fitting covers; waiting to take out the garbage until it’s close to collection time.

Instead of debating who’s to blame for the Libbytown infestation, Portland and MDOT officials should acknowledge their joint culpability, put in place evidence-based rat eradication measures (including public education) and help Libbytown residents drive away their unwanted new neighbors.