Eyeless Fish Navigates with Mouth Suction

As bats squeak and swoop through pitch-black Mexican caves, the pale fish that inhabit the pools below them perform a soundless imitation. These fish are blind but sense the world through subtle pressure changes on their skin. To navigate the cave floors, they also use a tool that's never been observed in another animal: the waves of suction they make each time they open and close their mouths. These pulses warn them of nearby obstacles like the calls of an echolocating bat do. Mexican bl