Staff and volunteers at the Wildlife Rehabilitation Center of Minnesota in Roseville had a batty final week of the year when 60 big brown bats arrived at the rescue facility.

The bats had been hibernating in the roof of Mark Fischer's lake home in Miltona, Minn., north of Alexandria, and were discovered during an attic insulation project,

Fischer said he called around and couldn't find any great advice on what to do with all the bats until he found the rehab center.

Removing bats is relatively easy when they're hibernating but requires some care around the fragile toes they use to hang upside down, said Tami Vogel, center's executive director.

The trick is to keep them cold. As soon as bats awake, they begin to burn fat quickly. Without flying insects to eat, they go hungry and die, even in warmer winters like the one Minnesota is now experiencing.

Fischer drove the bats the more than two hours to Roseville. In the car, "I kept the temperature low because I knew they were hibernating, and then they don't move much," he said. "I just dressed warm inside. and I kept the temperature low."

Staff and volunteers then could do health checks, wake the bats gradually and hand feed them to hibernation weight. The bats could then be moved into the center's bat hibernaculum — a wine refrigerator outfitted to overwinter bats — to hibernate until spring.

"Basically, what we're doing is cycling through the bats. We're taking them out in batches, fattening them up and then putting them back into hibernation at a hibernation weight," Vogel said. In the spring, the bats will be returned to Miltona and released.

Big brown bats are native to Minnesota and have an important role in eating pests, including destructive moths. Vogel said that to her, the bat rescue is the perfect feel-good story to end 2023.

"I know bats aren't a favorite of a lot of people, but they have a very important role in our ecological systems," she said. "And when someone makes the time and effort to save bats, it always warms my heart."

Fischer emphasized the wildlife center's role in helping the bats and encouraged people to donate to support the facility. "They did such a great job there; it was incredible," he said.

The Wildlife Rehabilitation Center has resources for Minnesotans who find bats in their homes at wrcmn.org/FAQ.