Interestingly: If you choose to visit any of the caves, a free cave permit is required for all visitors including school groups. This is to prevent the spread of white-nose syndrome (WNS), a disease that kills bats, into the caves at Craters of the Moon. Any clothing or any other item that has been in any underground space such as another cave or mine cannot be worn into the caves at Craters of the Moon, even if it has been washed or decontaminated.