Kind of why I think it wasn't a horse fly that bit me that one day a few Summers ago, and think it was some sort of fly with a proboscis....
Or a mosquito that looks like a fly.
I'll get into the story, seeing as it's fitting for this thread.
One day, I was at my father's cousin's house for an annual (it's been on hiatus for the past 5 years, due to 9/11 and the cousin currently serving time in prison, that, and the house is pretty much not theirs anymore) family reunion-type event. I was in the pool enjoying myself, when suddenly I feel as if something is starting to suck the life out of my arm. Looking there, I see what looked like a fly on my arm, sucking my blood. I said in my mind "that doesn't look like a mosquito", and showed it to my father's various cousins who were in the pool with me, asking them what to do.
I didn't want to bash the thing with my other hand, because I don't want to feel something that big getting squished. They suggested I go underneath the water, and I did. It flew away, I came back up, blood appearing where it was devouring my life force shortly afterward. The wound healed as quickly as it appeared. Not itchy, so, uhh.....