Evolutionary chance made the barbastelle bat a specialist hunter, says study

Don't worry everyone, they still scream at their food. Barbastelle bats are just a little quieter.

The reason for the morphological limitation must be found in how bats emit their sound. Most bats call out of their mouths, and this allows them to emit loud sounds. Many gleaners, on the other hand, emit sound with their noses, and this makes their calls 20 dB lower.

Can you imagine screaming through your nose?