A fungal disease that has killed millions of North American bats is spreading and now has been detected in half of the United States.
Officials in Michigan and Wisconsin said Thursday they've confirmed that bats in their states have been diagnosed with white-nose syndrome, which first showed up in the U.S. in upstate New York in 2006.
The disease is named for the white fuzz it creates on the animals' noses, wings and tails. It causes hibernating bats to wake frequently, which saps their energy reserves and can cause them to starve or dehydrate before spring arrives.
In some caves where the disease has been spotted, more than 90 percent of bats have died.
Bats are valuable species because they eat insects that otherwise would damage crops and trees.
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