Did you know that there's a mouse that hunts scorpions and shrugs off their sting? How about a long-lived and cold-blooded mole-rat that's resistant to cancer? Check out...
- The Scorpion-Slaying Grasshopper Mouse (That Turns Venom Into a Painkiller)
- The Flood-Causing Nutria
- The Jumping Jerboa
- The Crop-Eating, Disease-Carrying, Fire-Starting Mice of Australia
- The Wonderfully Weird Naked Mole-Rat
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| Nutria can mangle flood defenses... (manfredrichter) |
The Scorpion-Slaying Grasshopper Mouse (That Turns Venom Into a Painkiller)
Most small creatures (and quite a few big ones) stay well clear of scorpions. Take the bark scorpion of Southwest America - its sting isn't lethal to a healthy adult human, but the pain is described as "intense." Most small animals quickly succumb to the paralytic venom... but not the grasshopper mouse.
It turns out that the rodent has a mutation that makes a natural antidote. Bark scorpion venom normally works by passing a signal along the Nav1.7 ion channel in each nerve... but in grasshopper mice, the venom was intercepted by proteins from the Nav1.8 ion channel. These proteins bind with the venom and neutralize it!
Not only does this protein prevent the venom from paralyzing (or even hurting) the mouse, the neutralized venom gets in the way of the pain-related ion channels and numbs all pain the rodent should feel for a while.
To cap off the absurdity of this diminutive creature, grasshopper mice howl into the moonlit night - researchers believe this may be a territorial display, but locals have nicked-named it the "werewolf" mouse!
The Flood-Causing Nutria
Rodents are famed for destroying crops, but this one adds insult to injury by causing floods!
Also known as coypu or swamp rats, Nutria make their homes in places with a lot of fresh water. They were introduced to the USA from South America during the peak of the fur trade... but established themselves as an invasive species when ranchers no-longer found them profitable.
Nutria reach about half a meter in body-length but resemble a mixture of guinea pig and rat - albeit boosted up to much larger proportions. They also have an incredible birth rate, with females producing litters of up to thirteen cubs three times per year. This birth rate suits their native territory in Bolivia and Southern Brazil (the drought-flood cycles ensure a high mortality rate) but the milder conditions found in the USA do little to keep the population in check. To make matters worse the nutria consume 25% of their body weight in plants each day, often gobbling up entire plants and leaving nothing that can grow back.
Adding insult to injury, nutria will dig holes through irrigation systems, under roads... and through flood defenses. Combined with vegetation-stripped land, the damage done by nutria vastly increases the risk of severe floods!
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| The jerboa is a big-eared acrobat... (Pei Yu) |
The Jumping Jerboa
Have you read the "Dune" series by Frank Herbert? If so, you might recognize these little fellows!
Small, bipedal and massive-eared rodents from the deserts of Africa and Eurasia, jerboa look like they come from an alien planet. In keeping with the Dune books, they even use an erratic gait (combining hops, leaps and dashes) to cross the sands.
The big party trick of these rodents is a powerful leap, one that can carry them ten times higher than their hips - and hurl them away from danger.
Jumping like this is incredibly costly - it's powered by muscular action (rather than energy stored by tendons) and trades efficiency for raw speed and power. On the plus side, it's fast enough to fling the rodent clear of a lunging predator or even a swooping bird... and the huge ears sported by the jerboa let it hear predators before it's too late!.
Of course, some cunning predators could estimate the direction of an escape leap and hit the rodent mid jump... but the jerboa has another trick. Researchers in the lab found it much harder to predict the leaps of a jerboa compared to quadrupedal rodents. They also noted that jerboa were far less anxious when in an open field than other rodents, suggesting that they were far more confident in their evasive tactics!
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| One is cute, but a swarm is not... (Alexas_Fotos) |
The Crop-Eating, Disease-Carrying, Fire-Starting Mice of Australia
You might be wondering why mice are on here - they don't really seem that remarkable, right? They're small, they're cute... but as Australia found out, in large numbers they can be as destructive as a biblical plague.
In 2021 a shortage of wild-growing food caused mass migration in the mouse population - the rodents were even turning to mass cannibalism in an attempt to stave off hunger. The mice traveled by foot but also as stowaways on vehicles, ravaging anything edible that they passed.
Here's where it gets really weird. The creatures explored houses and machinery, chewing their way through cables and pipes as they did. In fact, at least one family had their home burn down after mice chewed through electrical cables.
As a final cherry on top of this disastrous dessert, the furry swarm carried a bacterial infection with them called leptospirosis - a nasty condition that can take months to recover from!
The Wonderfully Weird Naked Mole-Rat
I don't think anyone would say the naked mole-rat is a beautiful animal (it's probably best described as having a face made for radio) but they do have a collection of amazing powers. For one thing, these long-lived rodents (they can reach 40 years old) seem to have better ways of repairing damaged DNA than humans do... and as a result, they seem highly resistant to age-related diseases (up to and including cancer!)
The naked mole-rats live in underground colonies and are highly adapted to subterranean life. They can deal with very poor quality air, surviving in concentrations of oxygen as low as 5% (we humans are used to 21%) for over 5 hours. Put in an environment with no oxygen whatsoever, the naked mole-rats collapse after around 30 seconds... but are still able to recover without any ill-effects after being asphyxiated for 18 minutes.
Most mammals rely on glucose to keep their body running, breaking it down using oxygen. Researchers have found that naked mole-rats are able to "switch" to a reserve of fructose instead, using an enzyme to break it down without needing oxygen!
Naked mole-rats are also resistant to the inflammatory pain caused by acid, which may help them deal with their carbon dioxide filled burrows. Funnily enough, living in a cramped and poorly ventilated set of tunnels lets carbon dioxide build up to high levels, something that cause the acidification of living flesh.
You might be wondering why they don't just come closer to the surface - well, the naked mole-rat uses its different tunnels to regulate its body temperature... because it's cold-blooded!
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