Sandflies: The Piranha of the Air!
"The earth shall quake before them; the heavens shall tremble: the sun and the moon shall be dark, and the stars shall withdraw their shining."
Joel 2:10
Having seen the massive black swarms of them with my own eyes, I have little doubt Joel was providing warning for us all to avoid these tiny terrors with due diligence!

Don't let their apparent diminutive size lull you into a false sense of security. As Theodore Roosevelt himself wrote about them during an expedition to New Zealand in 1914, entitled Through the New Zealand Wilderness:
"They are the most ferocious insects in the world," Roosevelt announced. "They will strip the skin off a hand incautiously waived in the air; they mutilate trampers -- in every town in New Zealand there are men who have been thus mutilated; they will rend and devour alive any wounded man or beast; for the scent of blood in the air excites them to madness!"
You might scoff, and think there's little to tales advanced from those long-ago tales from a previous century, but look at these pictures of their horrendous butcher-knife like jaws, and perhaps then, hopefully, you will begin to believe:

One local Kiwi (you can call him "Tim"), upon hearing a tourist mock the horrifying tales and fearing for his safety, led him to a nearby area littered with the bleached bones of sandfly victims and upon noting the continued look of disbelief on the tourist's face, exclaimed: "They've got huge, sharp-- eh-- they can fly about-- look at the bones!" Sad to say, that tourist failed to heed Tim's warning.
Still an unbeliever? *sigh* I knew it would eventually come to this. You see, Tim shared with me the coroner's pictures that were taken after the tourist blithely wandered right into a huge sandfly swarm with no protection. Warning: this image may be too gruesome for some; close your eyes and scroll past if you are squeamish.

I warned you, but did you listen to me? Oh, no, you knew it all, didn't you? Oh, it's just a harmless little fly, isn't it? Well, it's always the same. I always tell them--
*ahem* sorry about that, now where was I? Oh yes, how to avoid sandflies. Well, as far as I can tell, there really IS no way to avoid them; signs put up by the Department of Conservation might occasionally hint at the danger, but only using words like "If the sandflies bother you, try retreating further from the beach."
...IF?
It's obvious that governmental agencies here in this festering den fully intend any not fully conversant in the lore surrounding this airborne pestilence to be quickly and summarily dispatched by them! So, take heed this warning, and make sure to bundle up in kevlar from head to toe should you intend tramping in the bush; especially dangerous are the Western coastal areas of the South Island (for instance, the areas south of Haast Beach and Milford Sound). Nobody without a full beekeeping suit should venture to these places if they value their lives.
After the need for such gruesome warnings, perhaps a bit of the "lighter" side of horrors of New Zeland is in order?
coming soon...
The Head Raping Parrots!