The Host- Bat

I am a fan of Stephenie Meyer's book 'The Host', and I finally got around to seeing the movie.... Let me just say that it SUCKED!!! beyond any redeeming value, even to Meyer's most cult-like followers! Okay, I've got that off my chest; that's all I'll say of the movie unless anyone else wants to bash it in the comments with me.
So after being subjected to that carcinogenic pit of refuse, I read the book again to help restore the original's standing in my head. And I decided to draw what I liked best about the book: the aliens. (I know that the names are a bit misleading and unoriginal, but I didn't name them, Meyer did)

The Bats of the Singing World (a.k.a. Blind World or Planet of the Bats) are completely blind, using echolocation to navigate the marginally thicker airways of their world. They use a dolphin-like melon organ to amplify and project soundwaves and a pair of articulating "ear-rods" to pick up the echoes, giving them precise details of their surroundings. Bats feed on a stony, lichen-like substance that grows on the sides of cliffs and trees, using a pair of tooth-claws and tail-fingers to hold themselves in place while their radulae scrape the 'plant' from its anchorage. While they are blind, a few predators of their planet are not, so their distinctive coloration serves as rudimentary camouflage. In addition to their echolocation-focused systems, the Bats have a second, crescent-shaped melon that they use to produce a constant singing that signals to others of their kind their position, health, mood, social status, etc.
When the Souls came to their world, the Bats were barely beyond what we would call a "tribal" stage in their development, using only basic tools while social activities were gaining complexity and the forces of nature just being overcome to provide leisure.