MAMMOTH CAVE, Ky. (AP) -- The disease that has killed more than 6 million cave-dwelling bats in the United States is on the move, and wildlife biologists are worried.
At Mammoth Cave National Park in south-central Kentucky, a sign lets visitors know they will have to walk on bio-security mats after touring the largest known cave system in the world. Shoes must be scrubbed to help contain the spread of white-nose syndrome.
The disease was discovered in New York in 2006 and has spread to 25 states, as far south as near Atlanta, and five Canadian provinces.
In Tennessee and elsewhere, some caves are closed to the public.
Biologists don't believe the disease poses a health risk to humans, but some say the loss of bats could cost farmers and the economy billions of dollars.
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