Fill in the gaps with the most suitable words:

Bat Chat

Did you know that in 0) one bat-cave, you could find thousands?

1) ... ? Bats emit ultrasonic sounds 4) to bounce back to themselves, allowing them to judge the size and distance of objects. 5) short, they use their ears to "see"! Bats can achieve this with 6) incredible accuracy that they can even detect a tiny ant on the ground! Not 7) so that, but they also use their voices to sing like birds! Yet, unlike birds, bats sing in mostly ultrasonic frequencies that are usually 8) too high for humans to hear. In fact, bats have some of the most intricate communication systems in the animal kingdom. They actually use their songs to talk to each other, and have 9) distinctive found to have distinctive vocal patterns, just 10) like humans. Indeed, scientists 11) think so amazed by bats, they believe that by studying bat-language, they could provide better treatment 12) for human speech disorders.