There's a noise. I don't know what it is. It happens every so often near my computer. It's not a click, it's not a thud, it's not a snap or a rat-a-tat-tat.
It's sort of like a whud-tick. Not a loud one either. A soft whud-tick. It doesn't happen in a pattern, as far as I can tell. It just whud-tick's when it wants to.
I first noticed it about a week ago. Prior to that there was no whudding at all. I wondered then what the whud-tick was and what the whud-tick would say if it were actually given words.