The bat population in the Tennessee Valley is declining and biologists think they know why. They believe a disease called White Nose Syndrome is playing a role, and they worry fewer bats could mean more bugs.

The dark and damp environment is a perfect recipe for fungus to grow. That fungus can cause white nose syndrome. It's a disease that was discovered in 2006 in New York.

David Hedrick, a Conservation Progress Coordinator with the Chattanooga Zoo says, "During hibernation, their immune system kind of goes down low, shuts down a little bit, and that opens the door for them to become infected with white nose syndrome."

The fungus that causes it can be carried by hikers or cavers. It's not been known to make people sick, but it can hurt bats in the caves they visit.

Hedrick adds, "Tennessee has 16 species of bats, and a good number of those bats are species that hibernate in winter."

The fungus grows on a bat's nose and wings, which wakes the bat up during the winter months. If you see the bats flying around outside of a cave during the cool months, this is an indications the cave is contaminated, as this is their way of fighting off the disease.

Caves in Kentucky are asking people to take preventative measures.

Doug Ratchford, the General Manager Service Systems Associates with the Chattanooga Zoo says, "Everybody that's going in and out of caves, they're requiring people to go through foot baths, just to make sure you're sanitizing yourself."

Ratchford says protecting the only flying mammal is vital for our ecosystem. Fewer bats mean more insects to eat crops like corn and tomatoes. It's estimated that bats are worth roughly 300 millions dollars each year, keeping pests off their crops.

TVA has closed the Nickajack Cave to protect the colony of the gray bat. 

Have a weather-related story? Feel free to email Meteorologist Brittany Beggs.

CORRECTION: A previous version of this story included Ruby Falls as a location for bat tours. Ruby Falls does not offer this type of tour. We regret the error.