What possible ways would the human race have to detect alien creatures from The Thing franchise vs natural uninfected animals

Question

During the movies The Thing 1982 and its prequel 2011 the alien entity would take over an organism by replicating its host at the cellular level becoming genetic duplicates.

Of the few ways found to expose these alien beings included searing blood samples to test if it reacts in a defensive manner and attempts to escape damage (uncharacteristic of normal blood).

It was also found that the process of alien absorption rejected foreign objects from the bodies of the parasites host, effectively making that one way to tell if a human with known enhancements has been "replaced".

We know the alien can replicate canine and humans, therefore presumably all mammals. Perhaps even birds and insects.

My question is this: If the alien parasite were to successfully make its way to warmer climate and begin to infect the planets animals (human included) what possible ways would the human race have to detect alien creatures vs natural uninfected animals.

I envision the surviving humans in strongholds surrounded with flame throwers killing any animal that comes near. Those wanting admission would no doubt enter a screening room where the blood test could be administered. Blood sample tests are impractical for wild animals making safe travel neigh impossible.

I imagine some non human animals may be able to avoid the aliens sensing something wrong / unnatural but short of killing everything how can humans safely discern the difference.

Unless there is a way to detect these creatures there would be no practical way to fight back short of a mass nuclear cleansing and torching everything NOT confirmed clean. Scorched earth sterilization.

I have only seen the movie adaptations, perhaps there are other canonical clues that may bring hope to this besieged planet. Or are we truly doomed to assimilation?

Answer 1

From @UhlBelk's link in the other answer, it seems like the human race would pretty much be over.

Like a zombie, every time it kills/assimilates it increases it's numbers.
Unlike zombies it also has intelligence and absorbs the hosts memories.

It probably would be able to absorb animals and insects, though it is unknown how small a host can be and still have intelligence.
Not that it matters, as a semi intelligent Rat-Thing sneaking through tiny cracks and carrying Flea-Thing's running on pure instinct could bite and infect just as well, though the assimilation process would be slow at first.

For defense some kind of airlock type chamber, big enough for one person, where an automated blood sample could be taken (like in GATTACA) and tested with heat, and if the blood reacts then chamber fills with fire.

But it's a short term fix, as the Thing's numbers increase exponentially, survivors are assimilated and food runs out...

Edit:

The only possible way that the human race survives is if something is found that kills the Things but leaves non-things somewhat alone.

Something like chemotherapy drugs that kill fast multiplying cells might have a big effect, and could even stop the assimilation if caught early enough.

Fire unfortunately kills non-Things just as well, so it's not as useful as it might seem.

It's very possible that the Thing has other weaknesses that aren't discovered in the movies, since they had such a small lab to work with and the Thing sabotaged their work.

Best bet, get a few Thing samples and take them to a biological hot zone lab like the CDC, go on full lockdown and expose the samples to every known medicine and chemical, find out what slows it down, what hurts it, what kills it, and then figure out how to weaponize it.

Edit 2:

Long shot, but since the Thing absorbs memories, it is possible that it could begin to develop some humanity over time.

There is also the question of if some part of the assimilated person continues on after being assimilated, instead of being wholly consumed...
Unfortunately there is no evidence to support this theory at this time.

Answer 2

First of all, there's problem that aliens are limited in numbers and would have to arrive to the planet somehow. Assuming that the ship under ice was single and that wasn't some deliberate plan of invasion and he simply woke early. We have to remember that those aliens did not 'infect' humans, it was organism that assimilated humans (and other life forms), and had no apparent means of quick reproduction. One alien- one assimilated organism it seems. So if we won't sleep through the invasion, we could simply shoot them from the sky. If we can't, then it would be better to invade landing sites as soon as possible. If they are able to descend their ships and move away from it - nuke. And as to birds and insects - it's impossible. Those aliens had some sort of organs, or whatever. They would simply not fit in a small bird or insect. It would be safe to assume that large dog is smallest it can assimilate.

--EDIT2--

Above is a little wrong, since I was pointed to some article on the internet it seems that aliens can split into smaller, less intelligent beings. So there had to be a bug-repellent barrier around human enclaves (I assume bugs aren't intelligent enough to organise attacks or be any force in the war, only a threat that would have to be dealt with. Human forces would have to wear hazard suits and probably use some bug-repellent that kills bugs (small alien organism shouldn't have strength to repel it)

But if they successfully invade, it would be possible to create protected enclaves, ever growing and heavily defended. Animals can be checked the same way as humans, even without human interaction with animals - using machinery of some kind. So domestic animals and live stock wouldn't have to be killed on sight, simply led with robots to some pen waiting for a check.

Also remember assimilation is not immediate. Enclaves could be under constant surveillance and automated systems detecting any shapes that would not be human or animal - means alien.

--EDIT-- Oh, right i forgot about foreign objects in bodies, simply install in all humans and live stock some RFID and equip armed forces with RFID detectors that would point out warm objects that do not have chips in it. Put gates everywhere that would incinerate everything that does not have chip inside. Quite safe.