@Felthry I recommend the book too! The author gets really clever with them. Once it's figured out they're ultrasonic, there's a point where someone rigs up walkie talkies to let members of the tine be physically separate by quite a ways.
@emanate I can't help but think they sound really hot, personally >.>
@emanate ooh, I love that species concept! Now I want to do some writing along those lines....