Why do some houseflies buzz REALLY LOUDLY when they fly while others are silent?

Question

(And on a more metaphysical level, why do the loud ones always dive-bomb my ear when I'm trying to nap?)

Answer 1

Hahahahaha! I think the loud one's are just bigger...Have you cleaned your sills? Those suckers go dormant and wake up!

Answer 2

I think the loud ones might just hate you.;)

Just kidding!

The voice in my head always thinks that's what they sound like when the don't have that long to live. However, this voice tends to have irrational thoughts... on occasion.