Horrific

In War Of The Worlds (H.G. Wells 1898), the invading Martians are defeated by the common cold. Various iterations of a virus defeat aliens from other worlds, from influenza to computer viruses (as in Independence Day).

Fair enough, but what is good for the goose is good for the gander.

What if, instead of blasting humans with the sci-fi equivalent of training sun through a magnifying glass on ants, those small, agile, zigzagging orbs were acting like crop dusters and subtly sharing with us some of their alien nastiness? 

In nature as we know it, there are parasites that cause fish to flip upside down, flashing their white bellies to avian predators. Thus, the parasites enter birds, which is what they need for the next stage of their metamorphosis. For instance, the Eye Fluke.

The modern movie equivalent of the eye fluke is the young person, usually female, who is addicted to a "smart phone", and although being warned not to use it, they do so. Same with credit cards. But, I digress.

If I were an alien, would I deploy cyclospora? I think not. It might take two weeks to work, is not reliable, and although it might be amusing to watch ones enemies suffer from explosive diarrhea.... it is not efficient. Moreover, one might end up hoisted with ones own petard... (which means blown up with ones own bomb.)

In Day Of The Triffids, a cosmic fireworks display rendered every human blind who was not blind drunk or sleeping through the light show. I do not remember if the mobile, carnivorous plants (Triffids) had something to do with the light show, or if they simply took advantage.

We do have a "Flesh eating" bacteria crisis in the southern States. Also known as Vibrio Vulnificus, this is a bacteria that thrives in warm brackish water (mix of fresh and seawater) and also in inadequately (or raw) shellfish. Usually, the human sufferer has a wound which might be a slight as a recent body piercing --even a new tattoo!!!-- or a graze or cut from stepping on something sharp while paddling in flood waters.

Sorry, I have no conclusion.

All the best,

RowenaCherry