Bat infestation forces Austin, Minn., school district out of rented building

ROCHESTER — Holy infestation, Batman!

The Austin, Minn., school district had to prepare for more than just its curriculum at the start of the school year. Because of a significant bat problem, the district closed off its Community Learning Center at the end of August, shuffling programs to other schools.

The district rents space for the center from Queen of Angels Roman Catholic Church. In an Aug. 31 letter to parents, district officials said they closed down classes for Sept. 1-12 and resumed them on Tuesday.

Those classes will be carried out at other locations for the remainder of the school year "out of an abundance of caution," according to the letter, though district officials noted there were no student health or safety issues at the time.

Austin Superintendent Joey Page said church officials told them about the bats in late August. District officials chose the move after hearing how long it would take to remove the furry fliers.

"The response time for that is going to be far too long for us," Page said. "We've got to get our kids in school and get the year started for them."

The Community Learning Center hosts preschool classes, adult education courses and other programs.

The district has looked to transition out of the space in past years. A $25 million referendum in 2019 would have funded a new wing at Woodson Kindergarten Center for early childhood and preschool programs, but voters defeated the measure.

Page said the scheduling has put some strain on other buildings in the district, but the measure appears to work so far.

Bat infestations are common throughout Minnesota. Big brown bats and little brown bats are the main species that roost inside buildings here, but a recent fungal disease has depleted the little brown bat population across the county during the past few years, leaving big brown bats as the usual culprits.

Pest control companies seal and put one-way valves on potential bat entrances to a building and wait for the bats to leave on their own in search of food. Bats can get into a space with an opening as small as three-eighths of an inch.

That's the best practice to remove bats, as trapped and relocated bats are adept at finding roosts once more, and killing bats without sealing off entrances just makes room for the next colony.

"Exclusion … is really the only way to get bats out, and it's also one of the most humane ways to do it," Melissa Boman, a mammal specialist with the Minnesota Biological Survey, said.

Experts say it can take up to a week or longer to remove the flying mammals from a large public building like a school or library, but that depends on whether the bats want to leave.

Older buildings like churches, schools and libraries make the perfect place for bats to roost in the summer months as females prepare to give birth to pups. The warmer temperatures help gestation, and the Minnesota DNR recommends leaving bat colonies alone from May to August to accommodate expectant mothers.

At the same time, it's important to remove bats in autumn unless you want houseguests for the winter. Keith Markun, a wildlife supervisor with Varment Guard, said bats could go into hibernation as early as October if they can't find enough insects to feast on.

Property owners have more to worry about than rabies when it comes to an infestation — less than 1% of bats carry rabies, though the disease is deadly to humans if left untreated. Bat guano can be corrosive to wood and metal, while bat urine can crystalize into stalactite-like structures on ceilings and "bat bugs" that normally live off bats can spread throughout a building.

"Once they've been born and raised and bred inside of a structure, they typically just look for and go into another structure," Markun said. "Because that's what they know."