Ada County’s rat problem slipped through the cracks at the Capitol. What’s next?

Ryan Davidson spent a few summers killing pests around the Treasure Valley. Working for his dad’s control company, the Ada County commissioner saw bugs, mice and a host of other rodents — but never rats.

So he knew something was off when constituents started posting photos of rats — some dead, some very much alive — on social media a few years ago.

“I thought, ‘This is a new thing, and we might not be prepared for it,’ ” Davidson said.

In the 2026 legislative session, Davidson and the rest of the Ada County Commission spearheaded a push to get the state to act on rat control, something that they say they’re not empowered to do under Idaho law. The session ended in April with a losing scorecard for rat bills: While two passed the Senate, one was voted down in the House, and the second never came up for a House vote.

“We were supposed to have a path forward,” Senate Agricultural Affairs Chair Tammy Nichols, R-Middleton, told the Idaho Statesman in an interview Tuesday. In the waning days of the session, though, “I guess plans changed on the House side.”

Nichols championed the bipartisan effort to create some framework for eradicating invasive rats, which slip between the cracks of Idaho Code. As a new arrival — early reports began in Eagle around 2022, Davidson said — there’s no agency in the state tasked by law with controlling them. Now that the Legislature has left Boise, there likely won’t be for at least another year.

“They’ll still get calls,” Nichols said of county and local governments, “but right now there’s not a lot that they can do.”

“Moving forward, people in the Treasure Valley are going to have to be really mindful of what’s going on on their property,” she added. “Unfortunately, my concern is that when we come back into session next year, we’re going to have a bigger problem to contend with.”

Idaho rule leaves room for rats

Davidson told the Statesman that Ada County asked its prosecuting attorney to review state law to see if there are options to move against rats without legislative authority.

At the Capitol this session, the prevailing view was no.

That’s because Idaho subscribes to an 1868 legal doctrine known as Dillon’s Rule, which makes the state government the principal source of legal authority. Dillon’s Rule holds that Idaho’s state government created its cities and counties, and therefore cities and counties “are limited to the programs and procedures specifically established by the state legislature,” according to the National Association of Counties. Dillon’s Rule contrasts with home rule, which grants local governments power to act in areas not prohibited by the state.

Rats aren’t mentioned in state law, so smaller governments don’t have an inherent power to address them, Nichols and Davidson told the Statesman.

“We’re still trying to figure out what we have the power to do,” Davidson said.

Jurisdiction aside, there’s also the question of funding. Some lawmakers last winter viewed Nichols’ legislation — particularly one proposal to put rat control under the auspices of the state Department of Agriculture — as a bill waiting to come due. Other worries went the other way, fearing an unfunded mandate passed from the Statehouse to local governments.

The county might be able to fund rat control through a voter-approved abatement district, Davidson said; one already exists for mosquito control. In Davidson’s view of that model, a ballot measure would create a new taxing district, which would collect money to pay private pest control companies. But he’s reluctant to raise taxes, he said.

City budgets are tight, too, Davidson said, but he’s found early interest in forming an anti-rat coalition. Talks led by Ada County Emergency Management are in their early stages.

“There’s been talk,” according to Central District Health spokesperson Stephanie Geanopulos, but no concrete plans. Geanopulos herself had rats on her property and had to call a pest control company to deal with it. For now, that’s what she recommends others do, too.

“It’s certainly something that people are talking about,” she told the Statesman, “but as far as I know there’s no structure in place for eradication.”

In Eagle, the city is “aware of the problem,” spokesperson Laura Williams said, “but the wheels of government move slowly.” Like the state, the city doesn’t address rats in its code, and isn’t clear what it’s allowed to do about them. In the meantime, Eagle is in the same talks as Central District Health.

“We’re all in a holding pattern at the moment,” Williams said.

Maria Ortega, a spokesperson for the city of Boise, said the city “has been active in educating residents about how to deter/prevent rats.”

“This is a Treasure Valley issue, not just Boise’s, and Ada County has indicated that it wants to take the lead, at least last time they presented at City Council,” Ortega told the Statesman in an email.

Davidson said the city seemed “very interested” in working jointly to beat the rats back.

“We probably could handle it on our own if we had the money,” Davidson said. “Absent the funding, it’s going to be tough.”

What’s next?

House Agricultural Affairs Committee Chair Rep. Jerald Raymond, R-Menan, voted in favor of Nichols’ original bill to enlist the Department of Agriculture to manage rats. Nichols said she didn’t know why his committee didn’t take up her updated, pared-back version during the closing stretch of the 2026 session.

Neither did Davidson.

“If people want to send them pictures of dead rats,” he said, “I’d allow it.”

In a Monday interview, Nichols sounded confident that a stripped-down version — one that authorizes counties to take action against rats, but doesn’t earmark any money — could pass into law in the Legislature’s 2027 session.

“Sometimes, you just have to come back,” she said. “And I think we’ll probably need to.”

Until then, Nichols urged Treasure Valley property owners to take all the steps they could to keep rats off their land — though she still believed they’re a problem that requires a broad, coordinated response.

“Rats don’t know boundaries or borders — that doesn’t matter to them,” she said. “They’re not going to stay in the Treasure Valley or Boise for long. People need to be careful when they say it’s not their problem, because it usually doesn’t take long for them to become everybody’s problem.”