Rats filmed snatching bats from air | Hacker News Reader

Rats filmed snatching bats from air

science.org

153 pointsXzetaU889 comments

I've kept rats my whole life and on one hand I'm not surprised, they'll eat what seems like literally anything, on the other hand they seriously pick their battles, a rat isn't going to engage with anything it's unaware of, they have extreme neophobia so I'm somewhat surprised this rat felt the situation out enough that it was comfortable doing this, I'd guess it had spent a lot of time around the bats, also surprising because the rat is a bit on the chonky side to be opportunistically hunting that way. Interesting.

How do you think he got so chonky?

My rats were very picky eaters. The inside of a cucumber slice would be eaten leaving the skin behind for example.

that's not unusual; most rodents do it, and also ants and plecostomuses (although in their cases it may be less out of preference and more due to mouth limitations)

The skin of cucurbits is usually fairly high in cucurbitacins (usually much higher than the flesh).

true! But that's also because cucurbitacins, given the size of a rat I'd imagine it wouldn't have to eat much cucumber skin to get pretty sick.

Unlike bats, cucumber slices can be easily transported to a safe eating place, rarely fight back, and are ideally suitable for precision nibbling.

The rats here at Lund University hunt pigeons, friend of a friend took a video of a successful hunt just the other week, totally nuts. They wait in the bushes below the trees on campus, pounce on the pigeons when they land on the ground.

Would you like to share the video?

Two thoughts come to mind:

- the rats are effectively as blind as the bat in the dark, are they relying purely on sound and air currents to gauge their attack?

- and what a fantastic new path for pathogen transmission.

> the rats are effectively as blind as the bat in the dark

Are they? Aren't rats nocturnal in the first place, meaning evolution should have given them some benefit in that environment? AFAIK, rats have pretty OK contrast/motion detection even in low light situations.

I guess if "in the dark" means "low light" or "total darkness". You're probably right for "total darkness" but if it's "low light", I think the rats would "see" better than the bats.

You might be right. The paper mentioned the rats preferred hunting near the light barrier but also mentioned they probably climbed the fabric for an aerial advantage (they didn’t seem to prefer hunting near the light barrier once the fabric was removed).

That's right, rats eyes are mostly rod based, they are very optimized for contrast shifts in extremely low light. They're also mostly colour blind.

> and what a fantastic new path for pathogen transmission

Presumably it's been there for a long time and we just noticed.

>Presumably it's been there for a long time and we just noticed.

As a previous commenter noted, rats are an invasive species in the expanding human/wildland interface. So they will be encountering novel bat viruses.

There may be other existing bat to human transmission paths, but maybe not....

> "Presumably it's been there for a long time and we just noticed."

We just noticed bat snatching. I doubt it's new discovery that rats also eat bats whenever the opportunity comes knocking.

Also: Bats -> rats -> (house) cats -> humans.

I don't see how a new path for pathogen transmission is available?

Not necessarily a new path, but a previously unknown path. Any place that bats directly interact with ‘land mammals’ leads to a mess of viral recombination and reassortment… hence why the agriculture/wild interface in China is the site of so many spillovers. Rats especially carry similar viruses with many features that increase tropism, so the fact that rats are feeding on bats means we’re going to get a ton of crossover viruses especially well suited for transmission in mammals.

One such study’s key paragraph…

> While uncommon for coronaviruses of bats, furin cleavage sites are commonly found in coronaviruses of rodents and it is perhaps fitting to note that proteolytic processing of the coronavirus spike protein was first recognized in the model rodent coronavirus, murine hepatitis virus, MHV-A59 [53], with later analyses demonstrating the importance of furin for the proteolytic cleavage and function of its spike protein [54].

https://www.sciencedirect.com/science/article/pii/S235277142...

I don't think that is possible in practice? Rats and Bats diverged some 60 million years ago, they're far too host specific for anything new, and they have the same coevolution as bats to paramyxo and coronaviruses, I would presume that makes them immunologically resistant and ecologically poor hosts for any strains.

Edit, in fact the paper you link says exactly what I said I think? Rodent coronaviruses already evolved to use furin long ago. I think this paper just makes it even less likely tbh.

Might be wrong about this, but being so far removed and seemingly immunologically resistant is exactly what makes it a dangerous combination. Viruses mutate and recombine at an astonishing rate, so 99.9999% (?) of viral entities won't be able to make the jump between these species, but the one that can might have devastating consequences as it will be wildly different from anything that has infected rats before (and from there it's more likely to infect other mammal populations).

The more exposure between these populations the higher the likelihood that a crossover event occurs.

high mutation rate != high crossover rate, and immunological resistance != susceptibility to novel evolution. (it's actually the other way around)

Also to be super clear, I'm not saying rats are immune to bat viruses, I'm just saying in reality it's is too divergent for functional crossspecies transmission and both rats and bats already have their own established, evolved coronavirus ecosystems that solve the same problems (like furin cleavage above). It seems to me near impossible it could actually happen.

It’s incredibly common for bats and rats to be coinfected with the same viruses… this is literally why we were looking at pangolins and raccoon dogs and mink for SC2 and at masked palm civets and ferrets for SC1. The term of art here is “intermediate host”.

The virus doesn’t need to make the animal sick to increase its human transmission risk, it just needs to infect its cells and be in the same host as other circulating viruses to get the crossover and recombination events.

From early host analysis,

> For a precursor virus to acquire the genomic features suitable for human ACE2 receptor binding, an animal host would likely have to have a high population density to allow natural selection to proceed efficiently (27). It is interesting to note that rodent betacoronaviruses have the polybasic cleavage site (38). Considering the above, surveillance and whole genomic analysis of CoVs from rodents are important to elucidate whether these species have any role in the transmission cycle of the virus and to detect the emergence of possible recombinants involving CoVs from these species and those from bats. However, there is not yet any evidence on the role of rodents or squirrels as intermediate hosts.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7297130/

Or more direct examination of the FCS issue between rats and bats:

> Here, we examine the spike protein across coronaviruses identified in both bat and rodent species and address the role of furin as an activating protease. Utilizing two publicly available furin prediction algorithms (ProP and PiTou) and based on spike sequences reported in GenBank, we show that the S1/S2 furin cleavage site is typically not present in bat virus spike proteins but is common in rodent-associated sequences, and suggest this may have implications for zoonotic transfer. We provide a phylogenetic history of the Embecoviruses (betacoronavirus lineage 2a), including context for the use of furin as an activating protease for the viral spike protein. From a One Health perspective, continued rodent surveillance should be an important consideration in uncovering novel circulating coronaviruses.

https://www.sciencedirect.com/science/article/pii/S235277142...

Too much conflation going on at this point, feels like we’re getting to the point of talking past each other. My understanding is: crossspecies jumps need cellular compatibility, not just proximity. Resistance makes a host a dead end, not a mixing vessel. “Intermediate host” means one the virus can actually replicate in, not just be near. And parallel evolution isn’t the same thing as recombination.

I guess we are getting past each other. Not all viruses have the crosspieces compatibility, but many coronaviruses do. Rodents are extremely common intermediate hosts for bat viruses that later infect other animals. It’s a speculated source of a pig outbreak in China;

A possible scenario for such transmission may include bats infected with HKU2-like CoVs preying on insects near pig facilities, dropping contaminated feces that were later introduced into the pens somehow, by pig feed or some kind of animal (Fig. 4). According to our onsite observation in 2017, rodents were frequently visible in these pig farms. Notably, bat HKU2-like CoVs are clustered with rat CoVs in the genus Alphacoronavirus (Fig. 3). As we found that SeACoV infects different cell lines originating from rodents, and mice may be susceptible to SeACoV experimental infection (Yang et al., 2019b), we hypothesize that in such field conditions, rodents (especially wild rats) in the farms may eat pig feed contaminated by bat feces, becoming carriers of SeACoV (Fig. 4). Alternatively, if pigs became infected and shed SeACoV-positive feces, the virus could begin circulating in pig facilities. Contamination of pig feed, pig feces and water supplies by rodents could accumulate and develop into outbreaks of diarrhea in neonatal piglets (Fig. 4). Future studies on identifying HKU2-like CoV positive samples in rodents near pig farms are warranted to test this hypothesis.

Many rat coronaviruses are closer evolutionarily to specific bat coronaviruses than other closely related bat coronaviruses;

https://ars.els-cdn.com/content/image/1-s2.0-S01681702193067...

Bats are one of the largest disease reservoirs on the planet for all kinds nasty novel viruses that could potentially jump to humans.

Bats have crazy immune systems that let them harbor all kinds of nasty stuff without it killing them on account of their unclean communal living habitat. Bats are in close contact where waste and bodily fluids are constantly coming into contact with other members, and these all carry pathogens.

Bat immune systems evolved as a defense mechanism. Bat viral loads are high, and the viruses get to evolve rapidly, come into contact with other virus genomes, and essentially explore the state space of potential virus genomes quickly. Constantly evolving novel glycoproteins, etc. Bats are essentially a virus optimization battleground.

These rats are an invasive species (to the cave) that also live in close proximity to humans. They've just been discovered hunting bats, meaning they're coming into close contact with bat viruses and potentially serving to introduce these into rat and, possibly subsequently, human populations.

Additionally, if the viruses can jump to rats, they're in a state where they could already be primed to infect us.

Bat viruses are no joke. Since our immune systems aren't familiar with novel viruses, and the viruses aren't adapted to not kill their human hosts at first, novel bat viruses can do a lot of harm.

Are bat reservoirs an interesting way to study novel virus especially for easy preemptive discovery of anti-virus?

Last week I saw a couple of small hawks attacking a bat swarm as they came out of their cave at sunset. Less of a transmission vector probably, but there seems to be a lot more interaction between bats and other animals than I thought. I wonder if domestic cats attack bats.

> I wonder if domestic cats attack bats.

I have no doubt. Cats have an incredible prey drive, and it would be down right batty for them to have some sort of hardwiring to avoid bats when they happily attack moths who have a similar flight pattern. I haven’t personally seen one catch a bat, but it wouldn’t surprise me at all. A cursory search says indicates it happens.

Although for whatever reason I would be more concerned about a dog finding, rubbing in and eating a dead bat. I mean I don’t know what percentage of bats die while out, but it can’t be zero, and dogs—especially spitz-types—are remarkable at finding dead animals. Now that I think of it, I could easily imagine a person getting direct exposure to diseased bat remains through that vector. People typically put their hands on the shoulders of dogs and think little of it.

https://m.youtube.com/watch?v=X652RJtSWs8

> it would be down right batty for them to have some sort of hardwiring to avoid bats

My cat has a deeply-wired fear of raptors. Bats flutter around closer to the ground. But maybe bats benefit from that conflation?

My cat caught one a few weeks ago when it flew into our winter garden. Luckily I was fast enough to not let him bit the bat.

After seeing a street cat kill a scorpion I don't really think they're afraid of much.

Cats do attack bats. See https://www.sciencedirect.com/science/article/abs/pii/S16165...

More anecdotally, I knew a cat that brought in bats almost daily, which is why the owner had her vaccinated against rabies (classical rabies RABV has been extirpated here).

Rats becoming carriers of Lyssavirus would be quite alarming.

> - and what a fantastic new path for pathogen transmission.

on the bright side and if history is of any help, as long as future-to-be-debarred "experts" aren't doing gain-of-function research on bat viruses while lying about it, we don't have much to fear.

Official US Congress report, mandated under Biden and whose results came under Biden, says the virus has "characteristic not found in nature" and that a lab-leak is the most likely source:

https://oversight.house.gov/release/final-report-covid-selec...

And Peter Daszak has been debarred, defunded and prevented from ever receiving funding from the US again.

I'm more worried about humans lying and humans siding with lying humans to then lie some more, worldwide, to the public --for years before the truth finally came up to light-- much more than I'm about rats attacking bats.

>on the bright side

I wouldn't be so confident. HIV and Ebola came from the wild. Bird Flu also has the potential to be really bad.

> mandated under Biden and whose results came under Biden

You missed the part where the original mandate was along party lines with Democrats supporting it and Republicans not, to investigate how the Trump administration handled the pandemic response. Republicans took control of the House and then redefined the agenda to be their own partisan viewpoint, to confirm what they already believed about gain-of-function and lab leak theories. They produced a nice Big Beautiful Report with a debatable connection to facts, which is not surprising in the least.

> before the truth finally came up to light

If you are looking to politicians for the truth...

What’s so ‘new’ about it?

This is the funny thing about echolocation in the dark-- it gives the bat's position away to the rat as well.

> The behavior is all the more impressive given that the rodents hunt at night, when they are effectively blind; the rats may rely on their whiskers to detect changes in air currents caused by the bats’ flapping wings.

Textbook example of the blind eating the blind.

The question "do rats eat bats?" sounds like taken straight from Alice In Wonderland, and now, disturbingly, we know that the answer is positive.

I was trying to remember if it was "do cats eat bats" or "do rats eat bats." Turns out it was cats, and once again reality is stranger than fiction. :D

“And here Alice began to get rather sleepy, and went on saying to herself, in a dreamy sort of way, 'Do cats eat bats? Do cats eat bats?' and sometimes, 'Do bats eat cats?' for, you see, as she couldn't answer either question, it didn't much matter which way she put it.”

― Lewis Carroll Carroll, Alice’s Adventures in Wonderland / Through the Looking-Glass

Rats are extremely predatory, I once as a kid worked at a Reptile importer and a handful of rats escaped, they destroyed the mice from under their screen/grated cages. Almost as traumatic as when I learned how to dispatch an adult rat on the side of the table before feeding it off to the reptiles at 15 years old.

Hm, maybe I should get some rats to keep the mice out of my house. Of course then I'd have rats.

If you have mice you won't have rats. Mice can be a positive sign.

I have both. I've trapped both in the same trap on the same night.

Get yourself a nice black rat snake. (Unironically, it drives me up a wall when I hear about people trying to exterminate snakes and spiders; the only reason those are around is because their food is.)

I have a black widow problem. Their food is flying insects.... Any tips?

I wouldn't worry about them. A few thousand people get bit by them every year but there hasn't been a fatality in decades. They're very unlikely to bite and very unlikely to cause any harm at all even if they do bite.

Maybe get some sticky fly paper though.

What eats them? (Really, from a distance they seem unbeatable.)

Wasps

Daddy long-legs are known predators of Australian red-backs, while the American cellar spider supposedly hunts black widows.

> the only reason those are around is because their food is

For some reason everybody in my city is proudly boasting bout the recent large capybara population... And again, for some reason those same people didn't react well when jaguars decided to show up in the urban area.

People are stupid.

We have all of the above and more. Alas, my wife is more afraid of our rat and pine snakes than she is of mice and rats.

Fortunately, the pine snakes only try to move into our house and sheds once or twice a year or so.

Rats are brilliant animals, they’re just tiny dogs. If you treat your rats well, they would have no reason to attack mice and would co-exist (although your rats would probably get sick because of disease. Pet rats (fancy rats) are illness prone.)

Next step: get some turtles!

Rats are not predatory, they’re resourceful. You didn’t witness what rats do in the wild, you witnessed abused rats doing whatever they could to survive. Rats will eat mice if they need to but they will not seek them out when other food sources are available. You can’t judge the behavior of rodents when they are feeders. Mice would do the same thing. As would you and I.

But then we see the rats hunting bats...

> The behavior is all the more impressive given that the rodents hunt at night, when they are effectively blind

I can't access the paper to check if they verified it, but given there is a strong IR light, and even humans can see IR light if strong enough (and close enough in frequency, which is typically true for IR illumination for cameras), I wonder if that is true.

Snakes do it too. https://www.nationalgeographic.com/animals/article/kantemo-b...

If you like the idea of vicious rats, read British horror writer James Herbert’s The Rats.

The food chain myth destroyed so many people's minds. Wait until you hear that deer eat mice.

Horses eat chicks.

https://youtu.be/ZnYNmGMsU18

Or that chicken eat chicken.

I played bass for Snatching Bats

Never underestimate a rat

Rough life inside a cave.

weird my IP is blocked according to science.org website

When mammals hunt other mammals strange things can happen.

Covid-200

How do I know this is not Sora?

Sora is too smooth

One angle could be to consider it from a game theory perspective.

Is this the sort of organisation that would be negatively impacted by publishing unverified stories?

If so, what is the likelihood that the content is just Sora?

Game theory or Bayesian inference?

I'm an expert in neither, but I would say both?

I thought of game theory initially because I framed the situation as a repeated game, where every article published is a new round.

https://en.wikipedia.org/wiki/Repeated_game

But then I went and muddied it with the word "likelihood" :)

This is an important analysis to perform but it's far from a sure thing. Motives can be murky and hard to assess. Maybe there is one particular scientist that has a baby on the way and fears he is about to be laid off unless he can get a sensational article published asap. A little helping hand from ai could be just the thing, and it's based on a true story just touched up a little bit and besides it's not like the readers will suffer any real harm from this tiny little transgression. Just one little shortcut one little time off course after that it's right back to honest science.

Motives can be murky and hard to assess.

FOH with that FUD, if you care about corruption go after the obvious examples instead of making up new ones.

Chain of reputation. If you can trace back the claim to a person or persons who have reputation to stake on this, then it's unlikely to be completely fabricated.

There are tech-related ways to tell for now but eventually it's going to come back to this.

> Chain of reputation. If you can trace back the claim to a person or persons who have reputation to stake on this, then it's unlikely to be completely fabricated.

AKA "Provenance" but digital, for those who want to look at existing methodologies. https://en.wikipedia.org/wiki/Provenance

Additionally, in a very concrete technical sense, "whatever1" must rely on the "chain of reputation" of the https certificate system to have confidence that what they saw is not sora.

It is good to be skeptical, but there is a large amount of detail in the paper itself that would have taken quite a bit of effort to fabricate (for no good reason): https://www.sciencedirect.com/science/article/pii/S235198942...

There is enough detail there to book a trip to Germany and set up infrared cameras if we are so inclined, repeatability is a large part of science.

Because the person filming it brought the camera with approved government ID. Got their camera serial number recorded in the government database. The camera then embeds its serial number into the video using hidden watermarks. Just Joking .... for now.

The bat and rat were identified as non visa holders by ICE.

what about bats make them good carriers for disease?

great another disease vector from bats.

“Rat Eat Bat” is a more succinct title.

Why is this surprising, aren't rats used to torture?

rats !heart bats

Fucker, another reason to eradicate the pest.

Reply on news.ycombinator.com