Nuerbles have no mouths. They neither give anything or take anything from the environment. They have no need to make sounds, other than the squeaks and honks associated with sudden movements, since they prefer to communcate by a system of charades and tap dancing.
THE DIRTY STUFF:
The reproductive process of the Nuerbles has not been extensively studied, because nobody has yet been able to stop laughing long enough to take notes, but of all the naturally occurring lifeforms in the Cosmos, they most closely resemble the virus.