While Baltimore County has been losing population over the past four years, its rats have become a growing problem, spreading themselves far and wide.

The pesky rodents have migrated from the 25 communities where they’ve been a known problem — among them Dundalk, Essex and Middle River — to residential nooks, commercial corridors and multifamily dwellings throughout the nearly 600-square-mile county.

With the main pest control contractors busy taking care of the usual traps, Pete Gutwald, director of the county’s Department of Permits, Approvals and Inspections, thought they could use reinforcements.

Gutwald is asking the Baltimore County Council to approve three additional contractors for the county’s successful rat rubout program, which could cost a total of $1.5 million over five years.

The money comes from the county’s neglected property fund, which fills its coffers with fines paid by residents for code enforcement violations. The $1.5 million is the total amount the expanded program can use, though it may not need all of it.

Adding more contractors would allow the teams to cover different places at the same time.

“We want to be able to be more responsive,” Gutwald said. “When they [the pest control companies] are in the middle of doing an intensive program in one of the neighborhoods, they may be delayed getting into that other neighborhood to do a treatment.”

The rodent program is set up in tiers. The first includes education and outreach on how to prevent infestations. The second is one-time treatment. The third is an intensive eight-week treatment and monitoring.

Sometimes, code enforcement recommends rat abatement; sometimes, communities request it themselves.

When it’s determined that a community has a problem, a contractor visits the area and inspects for rat burrows in yards and storm drains, and then treats, collapses or fills those burrows.

Gutwald said the program has to be coordinated with managers of multifamily residential buildings, so the rats don’t get pushed out of one area and settle immediately into another.

Also keeping the populations down is a twice-a-week trash pickup in neighborhoods with a high volume of rats. Typically, Baltimore County communities get trash pickup once a week.

Rats are an issue anywhere there is trash, abandoned property, restaurants, hotels, alleys and bars — essentially, all over the city and county. Baltimore City is so synonymous with rats that shops sell their likeness on bumper stickers. The city, too, contends with high numbers and planned to start administering rodent birth control to reduce its numbers.

And though no one has counted rodents in either jurisdiction in years, a National Library of Medicine study in 2005 estimated that Baltimore was home to around 48,000 of them, a population virtually unchanged in more than half a century despite robust efforts to eradicate them. Rats multiply like, well, rats.

The push for county pest control began in 2016, when East Side residents flooded council chambers to ask for help reducing their rodents. A local business owner, fed up with the furry vermin bused the residents to Towson so they could testify.

They wore T-shirts asking for help and brandished signs with drawings of rats on them with red Xs through their bodies, according to TV news reports. Councilman Todd Crandell, a Republican who represents the area, told them to come as their voices would be more effective than his alone.

Crandell said that, if a resident drove down an alley and turned their lights on, “you’d just see the alley crawling. It was really bad.”

The administration listened and implemented the tiered abatement program.

Crandell said he went from hearing around 100 complaints a month to almost zero. The abatement helped, but so did an assertive public education campaign about closing trash cans and sweeping alleys, and other efforts to cut down on what a rat might consider a set-out buffet.

“It was a remarkable turnaround for a problem that was was really out of control,” Crandell said at a council work session Tuesday. “It’s a model for some other jurisdictions facing similar problems.”

Councilman Julian Jones agreed with Crandell, saying the 2016 rat rally showed strength in numbers and democracy in action.

“I used that as a case study to explain to the citizens all the time the power that they have, that the system does, in fact, work when you show up, and especially in numbers, and advocate for something that’s important to you and your community,” said Jones, a Woodstock Democrat. “Some of them had some very chilling examples of what they were going through, fearful for their kids. And so I’m glad we were able to take care of that problem.”

Gutwald also agreed with Crandell’s assessment that complaints have dropped, which he credits to education, better trash lids, extra trash pickups and discouraging the practice of feeding feral cats.

Unlike the city, Gutwald isn’t implementing birth control. The tried-and-true approach has worked.

The council will vote on the contract for the additional pest control companies at its legislative hearing next Monday. It’s expected to pass.