"Did I mention that they can be VOCAL, and sometimes make clicking sounds??"
That is an awesome vivarium setup you have for the snake! However, the "clicking" sounds you hear are not the snake being vocal trying to talk to you, but rather it is telling you it might have a respiratory issue that needs to be addressed. Clicking, popping, and any other sounds are not good signs to hear from snake, and are very typical of respiratory infections.
~Doug
-----
"a snake in the grass is a GOOD thing" 
