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Comment by joncrane | Hacker News Reader

When I read that article, all I could think of was this video: https://www.youtube.com/watch?v=l2Pyu-Cj0gg

(In case you're sensitive, it's farmers using pitchforks to turn soil in a fallow or recently harvested field that is ridden with rats, which flushes the rats. There are a handful of ratting dogs milling about which immediately chase and kill the rats. The way they do it is the dog grabs the rat in it's mouth and shakes its head wildly. This breaks the rat's back and stuns it. It's actually pretty impressive, if violent and macabre.)

I think there are dogs that would find it fun as heck to live in that area of Australia for a few weeks.

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> "The way they do it is the dog grabs the rat in it's mouth and shakes its head wildly."

my dog is a terrier/spitz mix and shows this behavior in play (from the terrier side, the spitz side just makes her pretty =). she'll grab a stick or other small item and shake it wildly while bucking about. most people think it's hilarious until i tell them why she does it. =D

My 7lb cotton ball Maltese does the same thing. It's hilarious. He also loves to chase squirrels. Same dog yelped like he was being flayed alive when a neighborhood cat playfully swatted his nose. Ridiculous creature.

I love that description, thanks.

Years back I worked on a "configure a dog" educational interactive. IIRC, dogs share a common hunting sequence of behaviors, and some of their domesticated diversity stems from being able to genetically adjust the strength of those behaviors. So a retriever for instance, has the "bite hard" and "shake it" dialed down, and the "carry it home" dialed up.

Sounds like an RPG. haha

Interesting analogy. I recently saw outreach content that described rain/snow/hail formation in terms of a cooking recipe (eg, stir hail several times up and down past the frost line until it grows to ...). I wonder what other familiar frames might be used to scaffold understanding?

Some time back I was pondering how one might teach category theory to kids, by presenting it as cross-cutting patterns in everyday life (eg non-zero one-directional movement along a closed finite path eventually comes back around, as in simple board games, a clock's "we missed 12 today, but we can do it at 12 tomorrow", or "oops, passed an open parking spot - drive around the block".)

Many people forget that dog breeds exist for specific purposes and not just for looks. Just as mastiffs were bread to pull knights from horses, many small dogs were bread for rodent and pest control.

My dog is similar and caught a rat once in the garden. Ever heard a rat scream?

I ran around the corner to see what the commotion was and he had it in his jaws shaking his head violently.

Snapped the rats back, then dropped it and walked away. I put the rat out of its misery with a spade then buried it.

Talk about adrenaline!

But yeah rats scream like a little girl screams. It’s fucking horrifying.

Interesting - only time I've heard a rat scream from a dog killing it, it sounded exactly like a squeaky toy.

Which was a bit of a shocking realization.

Your adrenaline or the dogs?

Mine! The dog was licking where his balls used to be like nothing happened a few moments later. Way before my heart rate came down, he was napping.

My grandparents had a West Highland Terrier. Gentle little cream puff of a dog -- just like the foofoo dog you see on Cesar dog food. Except she had this little game she liked to play with the voles in the yard where she'd flip them into the air and fatally gore them with her teeth.

This breed was originally created to hunt small rodents on farms and such.

I am weird enough to see an optimalization problem in the video. How many dogs are too many? Obviously, two are better than one, but fifty isn't better than twenty.

Just saying.

Also, the comment saying "that is why dogs like squeaking toys" is spot on, though the idea is probably uncomfortable to regular dog owners.

You can also tell that some of the dogs are way more "into it" than others. It's a typical pareto distribution. 20% of the dogs are killing 80% of the rats.

If dogs could organize their own Olympic Games, I do not doubt that rat chasing would qualify as a discipline.

yeah, the scrawny white dog was definitely carrying the team

Optimization.

Here's an example of a dog optimizing a simple calculus problem! https://web.williams.edu/Mathematics/sjmiller/public_html/10...

Do deaf dogs not like squeaky toys?

If a branch falls in the forest, does the dog already cling to it?

It seems like the pitchforkers are the bottleneck. Probably could be solved with a tractor towing a harrow or plough, provided the dogs know to avoid getting ploughed themselves ;)

Or this guy, who uses trained mink and dogs for rat (and muskrat) control: https://www.youtube.com/watch?v=vvzZLI04_is

I've been ferreting for rabbits and the nets do most of the work, with the ferrets popping out later looking bemused after not catching anything. But those minks are insanely fast and brutal.

There's an entire category of dog bred entirely for that purpose.

https://en.wikipedia.org/wiki/Ratter_(dog)

That was an incredibly interesting watch, I had no idea this was a thing.

Is there something special about where they're digging for it to be plagued with such a large amount of rats? It looks like it would take weeks to cover all of their land with this digging + dog method.

My guess is that it's a field that was harvested in the past weeks. Harvesting crops makes a lot of edible material fall to the ground. I believe the "leftovers" from the harvest attracts the rats.

It looks maby like the remains of a row of haylage. Basically chopped corn, stalk and all, which is used to feed livestock. Usually you see this stuff in long white bags in the US country side, but there are multiple ways to store it. The stuff smells ferocious and self ferments. So they've probably used up the previous years haylage pile and now they are cleaning house so the rats don't totally mow down the spring planting their about to do.

I think 30 secs in shows a building on skids. It’s probably something like a chicken house that has been moved across the field. The rats are in amongst the old poop.

It's not a regular field.

That building you can see at about 30 seconds in is on skids, it is a barn/coop for chickens (or perhaps some other similarly small and light animal).

The bottom of the building is slatted to allow waste and other debris to fall through.

Because it's warm, and there's a constant sufficient supply of food it's an attractive home for rats and mice.

On some kind of regular schedule, the barn will be pulled along to a new location to allow the droppings/waste to be cleaned up, and the rats to be killed off.

thanks so much. appreciate this context :)

I wonder how many cats every house needs to rid it of mice. Given the volume, I doubt there are enough cats in Australia to even make a dent.

Cats are incredibly efficient hunters. I’d venture that 1-2 per household would quickly make a huge difference in the population, although a good number of those would have to be outdoor / barn / feral cats to have along term effect.

Disneyland has roughly 400 cats that keep the park largely rodent free, which is a minor miracle given the amount of food there is there.

Plus, you'd see a noticeable decline in local birds, which might not be desirable.

* Except a few giant rodents they largely stay away from

ROUSes?

> largely rodent free

Oh, the irony.

Mickey Mouse begs to differ :-)

I’m Turkish and I find it interesting that the US and European cities are dealing with mouse / rat issues. We have tons of cats roaming the streets. I guess that’s the reason but I have ever seen one or maybe 2 live rats in my entire life.

When I visited Athens, the massive colonies of feral cats were very notable. They could take over parks.

American culture is specifically oriented toward preventing this kind of thing from happening. A feral cat is judged to be in need of a home. And there is a very widespread popular effort to say that you are doing something immoral if you don't spay your cat -- if a fertile cat did go feral, it might have children!

I live in a major us city and there has to be 30+ feral cats within my block it's crazy.

That would be a pitifully small number compared to a park in Athens.

Hardly any then compared to Turkey!

There’d be at least a couple hundred in any one block. Thousands at night.

Some of those folks say they believe in animal rights too.

Keeping someone captive and ending their ability to reproduce seems more like abuse than love.

An animal rights activist is also going to take into account the quality of life of birds and other animals that cats slaughter by the billions.

That's the case for putting all predatory animals in zoos and feeding them vegetarian diets. Ending nature as we know it.

In the northeastern US, when I was growing up, I don't think there were a lot of predators of cats. People had "outdoor cats" who would stop by for a free meal, but not live inside.

But coyotes and maybe even wolves have become more common. Such that I remember people remarking about how a housecat wouldn't last long if left to roam. The predators may have increased due to other prey becoming more common as well, like turkeys.

In Israel too. Although they prefer going after rubbish. They say the British Mandate brought them in to deal with the rodent problem.

Australia actually started a program to kill off feral cat populations a few years ago

Maybe that's the root cause of the problem.

These mice plagues are a cyclic phenomena. I remember being in one in 1973, living in a small town in the wheat belt. Australia - land of floods, fires and pest plagues.

In Australia feral cats are culled since they kill the native animals.

There's even a guy that skins them and turns then into stubby holders.

https://youtu.be/VaB9J8JHVxI

I'm always surprised that cats are able to dominate ecosystems like this. You'd think a local apex predator would have filled that niche and been better adapted to the environment.

Pound for pound, it's hard to think of a more effective hunter than a cat.

Their skill set is absurd.

Absolutely silent, leap multiple times their body length, jaws & claws, climb, extremely agile / flexible and fast.

Decent hearing, great eyesight

>Pound for pound, it's hard to think of a more effective hunter than a cat.

Owls. The larger ones will kill even cats.

Owls aren't as prolific though if pest control is your goal. A cat will happily kill a dozen mice and eat exactly one. They are adorable murder-machines.

Marsupial lions were believed to fill this gap in the food chain. Unfortunately, they died out 60,000 years ago. Now cats and foxes are hunting native species, some faster than is sustainable. Eventually an equilibrium will be found, where the wild cat and fox populations can’t be sustained due to over-hunting, but it will likely come at the cost of many native species disappearing.

Australia's birds never had a local predator like the cat. They just had to keep an eye on the sky for birds of prey and maybe snakes.

It seems that efficient hunters are quite rare to evolve, as there have been lots of ecosystems totally turned on their head with the arrival of a new predator. Stoats, foxes, house cats have all found niches in ecosystems unfilled for hundreds of thousands of years and wiped out many local species. Or maybe the problem is that they are too good, and if left to themselves they would decimate their prey to the point they can't sustain their own numbers and die out; in the long term predators need to exist in an equilibrium.

Mice are instinctually afraid of the smell of cats, so the cat would not need to actually kill them to get the desired effect.

In this case however when we have hundreds of new mice each day, the fear effect and eating of mice would likely just be a drop in the bucket. The mice from nearby farmland and forests are fleeing starvation. A single house can collect and kill thousands a week and still more are coming, and the flood of mice can start up from apparently nowhere if you live near such areas. The only good thing is that it will stop at some point, and the professional traps can help to keep the situation at bay.

> I wonder how many cats every house needs to rid it of mice.

Anecdotally, one.

Obligatory Andrew Ucles tutorial on cats:

https://youtube.com/watch?v=4cTV6mKV6oE

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

"Feral cats are one of the major invasive species in Australia"

"In 2016, 29% of Australian households had a domesticated cat"

"Cats in Australia have no natural predators except dingoes and wedge-tailed eagles, and as a result, they are apex predators where neither the dingo nor the eagle exists"

Based on the given figure of 2 million or more feral cats in Australia, each killing 740 wild animals a year, that's 1.5 billion total.

So, given all that, I wonder why the mice are a problem at the moment.

My dog does this to his stuffed animals, blankets, etc. The agility of the motion is incredible.

Yep and the power and whip they get into it. The plastic end hit my leg once and left a huge welt. Can easy snap a rat spine. It’s completely baked into their dna too. You see the wolf inside.

If you look closely one of the dogs swallows a rat whole. Yum.

That's why these breads were called rattler in german.

https://de.m.wikipedia.org/wiki/Rattler

Thanks for sharing this - it is fascinating to see the dogs working together with people. They are very efficient!

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