RadioLab has an excellent mini-episode on the difficulties of communicating the subjective feeling of pain.
As you might expect, it is both wonderfully put together and unexpectedly beautiful in places, but for such a uncomfortable subject, it is also very funny.
Particularly wonderful is a segment on the originator of the Schmidt index that rates the intensity of insect sting pain from “Light, ephemeral, almost fruity” to “Pure, intense, brilliant pain”.
Link to RadioLab mini-episode on pain.
Mind Hacks 
Bugs and plants are quite inventive when it comes to pain. Who says they can’t communicate?
You’d think with sophisticated descriptions for taste like terroir we’d have a more organized way to qualify pain. Wouldn’t the most effective method for killing types of pain inform us about the nature of it?
Ice and jewelweed have always impressed me with their abilities in that regard.