Two people were found dead inside a duplex following a house fire in New Hampshire on Wednesday morning, the state fire marshal said.

There were no working smoke alarms inside the home when investigators arrived, officials said.

Shortly before 11 a.m. Wednesday, Weare Fire received a 911 call reporting a building fire on High Rock Road, State Fire Marshal Sean Toomey said Wednesday.

When firefighters arrived, they found a man and woman dead inside the home, said Toomey, whose office was called to the scene to investigate.

The victims were not identified on Wednesday. Autopsies will be conducted on Thursday to determine the cause and manner of their deaths, Toomey said.

The fire was isolated to one side of the home, in the living room area, Toomey said.

The cause of the fire remains under investigation.

Weare is a small town northwest of Manchester. The town’s population was 9,092 at the 2020 census.

This is a developing story. Check back for updates as more information becomes available.

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Now, it’s up to staff at the New Hampshire Society for the Prevention of Cruelty to Animals in Stratham to figure out how to care for the critters and what happens to them next. And no one expects that to happen overnight.

“It’s going to be a very long haul,” said Sheila Ryan, director of development and marketing at the NHSPCA,where shelter staff already have converted at least two rooms into rodent quarters, moving other animals to different wings to make room for the newcomers.

More mice were still en route to the shelter as of Monday, Ryan said, adding that shelter staff were making extra trips back to the man’s house to collect more of them.

“We do get cases sometimes where people have, you know, 40 cats or 60 dogs,” Ryan said. They also take in mice “on a regular basis.” But the sheer numbers in this instance are different than anything the Stratham shelter has seen before.

“My understanding is that they started off with a group of same-sex mice, and then added mice [of the opposite sex] to the mix, and breeding began,” said Ryan. The mice in the home were cohabitating and breeding in an uncontrolled way, she said.

Once mice start breeding, they can reproduce at a very fast pace, experts said.

In fact, even allowing just a few pet mice to reproduce, it would only take around seven months to end up with 800, according to Matthew MacManes, a professor of genome enabled biology at the University of New Hampshire, whose research includes mice.

MacManes said he had never heard of anything like this happening before. “Usually people would understand and stop this far before,” he said.

Mice can reproduce from the time they’re about 6 weeks old, and pregnancy lasts around 20 days, so it would only take about eight or nine weeks to create a new generation, given litter sizes ranging from six to eight pups and no mortality, according to MacManes.

He said without predators, their growth can quickly become exponential.

“I assume that this is a man or a family that just loved these animals, and whatever happened, this just sort of got out of control,” he said. “Maybe they didn’t realize the speed with which these animals could reproduce.”

Ryan Calsbeek, a professor of biological sciences at Dartmouth College, agreed: In the wild, predators keep rodents in check and can restore balance even if a population swells in a particular year.

But when mice are allowed to reproduce freely in the safety of captivity, “Your world can be overrun by rodents in very little time,” he said.

“I don’t know what this guy’s backstory is, if he was an enthusiast, or if he just accidentally had a breeding pair together and then didn’t know what to do with them, and things got out of hand,” said Calsbeek. “But either of those scenarios, if left unchecked, you can be overwhelmed readily.”

By Tuesday afternoon, Ryan estimated they had received at least 650 mice, and shelter staff had discovered a second species, taking in an additional 185 smooth-haired rats, which are only slightly larger than the fancy mice surrendered.Fancy mice — which come in a variety of colors — are a domesticated form of the house mouse that are sometimes raised to compete in shows.

She said given the right conditions, mice can make great, low-maintenance pets.

“They’re really entertaining to have in your home, and they’re adorable,” she said.

Some of the rodents already have found new homes. As of Monday, about 18 had been adopted, 50 had been placed on pregnancy watch in foster homes, and around 100 had been transferred to other animal shelters around the region from Connecticut, to Maine, and around New Hampshire, according to Ryan, who noted that more than 10 mice had to be euthanized because they were sick.

She said the community has responded with an outpouring of donations: tanks, food, treats, and wheels on which the rodents to play.

Still, Ryan said the process of adopting the rodents could take several months.

“It’s a niche market,” Ryan said. “Not everybody sees the joy in mice.”

Some of the rodents are up for adoption by the NHSPCA. The organization also publishes a wish list online of needed items, and they accept donations to an SOS Fund for neglected animals.

Amanda Gokee can be reached at amanda.gokee@globe.com. Follow her @amanda_gokee.

New Hampshire’s $100 million housing investment, InvestNH, is starting to pay off.

“InvestNH was absolutely critical in allowing more housing to be built,” said developer Jack Franks.

Franks, president and CEO of Avanru Development Group, said InvestNH’s help was key to some of his new affordable housing projects in Newport, Swanzey, and Hillsborough.

“Hillsborough would not have happened,” Franks pointed out.

Polls consistently show housing costs are a top priority for Granite Staters, and many of the state’s employers say housing is one their biggest challenges in attracting quality workers. Using federal ARPA relief funds to get more apartments and homes built, InvestNH is making a difference, though there’s still a long way to go.

“This crisis is not going to be solved overnight, but we are working with local leaders to get them the resources they need to match housing needs in their community,” said Department of Business and Economic Affairs Commissioner Taylor Caswell.

Administered by the BEA, InvestNH has already impacted more than 4,657 new housing units throughout the state, according to Caswell, with more to come.

BEA worked through InvestNH to create a capital grant program to fund the development of affordable housing; a demolition program to assist municipalities in preparing for or addressing housing challenges and project developments in older dilapidated properties; a per-unit incentive grant program that awarded municipalities $10,000 per unit of approved affordable housing, and the Housing Opportunities program, which assisted 67 communities to review and develop planning and zoning strategies to facilitate appropriate housing in their towns.

“The goal with these one-time funds has been to help accelerate affordable housing units getting to market and setting the stage for more private investment in affordable housing statewide by providing incentives and resources to local communities,” Caswell said.

BEA used InvestNH to fund: $64 million for the Capital Grant program that impacted 1,605 new units; $16.2 million for the Per Unit Grants program that impacted 1,910 units; $11.5 for the Demolition Grants program that impacted 2,302 units; and $7.9 million for the Housing Opportunity Planning Grants program that went to 67 communities throughout the state.

BEA’s new state Housing Champions program will soon be able to continue the InvestNH programs, thanks to state general funds totaling $15 million.

Even with InvestNH, New Hampshire has a vacancy rate of around 1 percent or less, according to Franks, leaving Granite Staters to pay more for rent or looking out of state for a decent home they can afford.

“It’s beyond critical mass at this point. It’s at absurdity, the amount of housing that’s needed in the state,” Franks said.

Of his three new developments, two were fully rented soon after opening. Both the Swanzey and Newport apartment projects now have waiting lists, and the Hillsborough development is taking applications now.

The biggest obstacle to building more affordable housing that Franks encounters are the sometimes redundant and contradictory local regulations that slow construction, or stymie projects altogether. Franks hopes incoming Gov. Kelly Ayotte will work to streamline those regulations and cut the red tape that make the housing crisis worse. 

Ayotte told NHJournal she’s ready to help.

“Tackling New Hampshire’s housing crisis is a key priority for my administration — we need more housing for our workforce, our seniors, our families, and every community across our state,” Ayotte said. “As Governor, I’ll work to streamline the state permitting process, cut unnecessary red tape that creates barriers to construction, and bring stakeholders together to discuss how we can incentivize construction of more affordable housing while respecting local control. Working together, we’ll keep New Hampshire moving in the right direction.”