Conversations with Flies

Today, I saw a fly perched on a door in my home. Curiously enough, it did not stir when I swatted. For the first time I touched a fly's wing for a decent length of time without it flying away. I was shocked that this fly was not disturbed by the movement of my hand, or by the feeling of my touch. Eventually, it flew away.

It was strange. Then again, why should a fly be afraid of me?