Fun fact: an average-sized colony of bats in one summer will eat about 600 million bugs.
A fact that's not fun: a disease that's fatal to bats is spreading through Minnesota – and killed a majority of the ones in the state's largest colony this winter.
It's called white nose syndrome and the Minnesota DNR said Thursday it has turned up among hibernating bats in five more counties. They already knew it had a foothold at Soudan Underground Mine on the Iron Range. The agency says the number of bats there has dropped 73 percent since white nose syndrome was confirmed a year ago.
It's in southern Minnesota now, too
Soudan Mine – Minnesota's first iron ore mine – is a huge network of underground tunnels and mines that's actually a state park. The 15,000 bats that usually hibernate there make it the state's biggest colony, the Duluth News Tribune says.
But park manager Jim Essig tells the paper this year there are so many dead bats at the mine's entrance, it's hard to count them all.
Now the DNR says the bat-killing fungus is also in southeastern Minnesota (Goodhue and Fillmore Counties), the Twin Cities area (Dakota and Washington Counties) and the northwestern part of the state (Becker County).
Doesn't hurt other animals
White nose syndrome is not known to affect people, pets, livestock, or any wildlife besides bats.
Not all bats are affected, either – only the ones that hibernate. That includes four of the seven kinds of bats in Minnesota. The northern long-eared bat has been especially hard hit in other states and it's now classified as a threatened species by the Fish & Wildlife Service.
It's only been 10 years since white nose syndrome was first seen in North America. But in that time it has spread to more than 30 states and five Canadian provinces, killing more than 5 million bats, the DNR says.
How to help
Once the disease reaches a cave where bats are hibernating, it will spread through the whole colony. So biologists want to keep it from reaching new caves, if possible.
There's not much we can do about infected bats flying to new caves, but people who explore caves can help by not wearing the same clothes or shoes into more than one cave. Scientists say a regular washing machine will not remove the tiny spores that carry white nose syndrome.
The Fish & Wildlife Service has some pretty in-depth decontamination protocols. They also want landowners who have caves on their property to learn more about white nose syndrome and how to limit its spread.