The US Federal Emergency Management Agency along with the Centre for Disease Control, used a zombie outbreak scenario in 2012 to teach citizens to prepare for emergency.

FLESH is food  and the fresher the better. It's something the zombies know. Probably the only thing, actually.

But what about their own dead - or rather, undead - flesh?

It's carrion.

And that's good news for the hipster tribes who spend weekends dressing up as zombies while worrying just what they would/will do if/when Day of The Dead actually arrives. If they survive that initial frenzy, they can sit back and watch Mother Nature do the rest.

US National Wildlife Federation naturalist David Mizejewski has put the matter into perspective, stating this planet's fauna would deal with such animated evil "brutally, and without quarter".

"Relax," he writes. "Next time you're lying in bed, unable to fall asleep thanks to the vague anxiety of half-rotten corpses munching on you in the dark, remember this: if there was ever a zombie uprising, wildlife would kick its ass."

Birds, bears and even blowflies would be an unmatched arsenal against an army of mindless, moaning corpses like The Walking Dead - a relief for the hit TV show's characters such as Rick Grimes.

But what is nature's most secret weapon?

Bacteria.

"It can obliterate a dead body in surprisingly little time," Mizejewski said. "Mother Nature doesn't let anything go to waste."

It's a lesson seemingly lost since H.G Wells repelled an invasion from Mars with the despised, diminutive creatures.

As he writes in his concluding chapter to War of The Worlds in 1897: "(The) Martians - dead! - slain by the putrefactive and disease bacteria against which their systems were unprepared; slain, after all man's devices had failed, by the humblest things that God, in his wisdom, has put upon this earth."

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Zombies are no less vulnerable.

"Bacteria, fungi, moulds, insects such as fly maggots or flesh-eating beetles, and other invertebrates, all make up nature's diminutive clean-up crew," Mizejewski writes.

"Zombies, with their rotting flesh, are obviously not immune to these decomposers - what do you think causes the rotting effect?

"The clumsy undead wouldn't have the dexterity to pick off these decomposers, even if they could see or feel them.

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"It would just be a matter of time. Stripped of all soft tissue, including brains, the zombies would be reduced to hollowed-out skeletons."

Zombies would shamble ominously for little more than a week, as this timelapse video proves:

While the subject is fun, Mizejewski says it contains a serious message.

"In reality, however, the battle between wildlife and living humans is not going so well for the wildlife," he writes.

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"Sadly, much of our continent's wildlife has disappeared, and many species continue to decline. Habitat loss, invasive species and climate change are just some of the human-induced challenges our wildlife are facing."

So just what does Mother Nature have in its anti-undead arsenal?

BIRDS: A wide variety of birds are scavengers. Vultures, eagles, hawks, magpies - you see them on the side of the highway hovering over roadkill. The same would apply if the corpses were (slightly) animated. Birds, however, don't like to put much effort into carrion. They'd wait until something bigger had done enough damage to make their prey easy pickings.

BEASTS: Most high-end predators will see a horde of corpses as a fast-food delivery service. Sure, zombies could possibly swarm over individual animals. But most are built for speed and strength far in excess of even healthy humans. Bears could easily rip off limbs at a stroke. Wolves could dart in to take down zombies one by one - biting through the vital tendons in the backs of their legs. Wild cats, however, prefer fresh prey - so they'd probably simply turn up their noses as older undead march by. But fresh zombies would be another matter, and a quick, crushing bite to the back of the head would eliminate any threat it may pose. And crocodiles? "Soft zombie flesh would melt in their mouths like butter," Mizejewski writes.

BUGS: Ants. Blowflies. Beetles. They're everywhere and all thrive on daily doses of dead flesh. While the sight of maggots may turn our stomachs, remember: They'll be the ones to turn zombie stomachs into mulch. "It might take a few weeks per zombie, but they'd get the job done," Mizejewski writes.

As he had the first word, here's H.G. Well's last word on the might of bacteria:

"For so it had come about, as indeed I and many men might have foreseen had not terror and disaster blinded our minds. These germs of disease have taken toll of humanity since the beginning of things-taken toll of our prehuman ancestors since life began here. But by virtue of this natural selection of our kind we have developed resisting power; to no germs do we succumb without a struggle, and to many those that cause putrefaction in dead matter, for instance-our living frames are altogether immune....

"Already when I watched them they were irrevocably doomed, dying and rotting even as they went to and fro. It was inevitable. By the toll of a billion deaths man has bought his birthright of the earth, and it is his against all comers; it would still be his were the Martians ten times as mighty as they are.

"For neither do men live nor die in vain."