Bug noise

click?
sing?
buzz? Their name is from the Latin for buzz.

Can you just use "the sound of the cicadas . . . "?

I did some research and many websites describe it as a buzzing, whirring, ratcheting or snapping sound. I watched a youtube video and to me it sounds like electricity.

Soooo maybe they, buzwhirratchshap?

"whirring" is not a bad suggestion.

I would have said 'to chirp', but I'm not even a native speaker. Translating from German, my online dictionary also suggests 'to chirr'.

I was going to chime in with singing or buzzing (per Wikipedia page).
http://en.wikipedia.org/wiki/Cicada

Actually...

I believe the tech term is that they stridulate.

I think I've most often read/heard the term "buzzing" used. And I can't stand the damned things. Sound drives me nuts.

Around here, where the wind comes sweeping down the plains, we just say they buzz.

Buzzing, whining, chattering, keening, humming (like power lines)...

How about clittered?