You take a deep breath blow into the whistle. A group of bats sleeping on the ceiling erupt in shrieks and scatter far above your head, the sound of their squeaks and beatings wings filling the cavern. You hear small splashing sounds followed by howling screams that sound disturbingly human coming from all around you. After a few moments of this another enormous, low groan fills the cavern, louder than the first time. You clasp your hands over your ears as your entire body shakes with the sound. Silence once again returns to the cavern. You wait and listen, but nothing else happens. You put your whistle away. You can knock on the door, peek in the windows, or you can hide and wait to see if anyone comes out. You can also try using your flashlight.