The number of bats inhabiting a large cave may be astoundingly large. For example, hundreds of thousands of the animals can be observed in the evening flight of bats from Carlsbad Caverns. Because lack of sunlight precludes green-plant growth, fungi make up the only plant life that can grow in caves. Groundwaters containing dissolved organic substances frequently provide nutrients for the fungi. The science of cave study is termed speleology.
Speleologists use many special contrivances and methods in exploring caves.
One technique is the use of dye stains to reveal the outlets of complicated underground-stream systems. Use of special shoes, safety helmets, flexible ladders and cables, and dependable lamps enables present-day speleologists to explore the recesses of large caves much more thoroughly than was formerly possible.