Some show caves can also be important shelters for different species of bats. Big bats colonies can form for hibernation during the winter or for maternity during the summer. In some of these caves, the "marriage" between tourists and bats has a long history. However, an in depth study was never done and nobody looked on the microbiological impact of bats on the air quality. By taking air samples from caves with bats we want to figure out whether air is clean enough for human breath.