trying to drink from a smooth metal plate.
For bats, any smooth, horizontal surface is water. That’s true even if vision, olfaction or touch tells them that the surface is actually a metal, plastic or wooden plate. Bats therefore rely more on their ears than on any other sensory system. This is due to how smooth surfaces reflect the echolocation calls of bats: they act just like mirrors. In nature there are no other extended, smooth surfaces, so these mirror properties prove to be a reliable feature for recognition of water surfaces.