TRAVERSE CITY, Mich. - A fungal disease that has killed millions of North American bats is spreading and now has been detected in half of the United States, including Wisconsin and Michigan.

Officials in Wisconsin confirm that bats in their state have been diagnosed with white-nose syndrome, which first showed up in the U.S. in upstate New York in 2006. Researchers officially confirmed the presence of white-nose disease found in a single mine located in Grant County on March 28.

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.

An email sent out by the Wisconsin Bat Project breaks the news to state scientists and bat-backers. It reads:

"We are writing with unfortunate news. The presence of the bat disease white-nose syndrome (WNS) was recently confirmed in Wisconsin. On March 28th the disease was detected in a single mine in Grant County by WDNR and USGS staff conducting WNS field research and routine WNS surveillance. The presence of the disease was later confirmed by the USGS National Wildlife Health Center."