Episode 33 – Southern Grasshopper Mouse: The Wasteland Warrior

“…and today we’re talking about a creature that is the half-orc barbarian class of mice and would give Cluny the Scourge a run for his money.”


The sonoran desert can be a hard place to find a good meal, especially for a hungry mouse. Plus, what can you do when one of your favorite meals also packs one of the most powerful stings in North America? Sometimes, survival comes down to chemical warfare and an aggressive attitude in Life, Death, and Taxonomy.

Measure Up

Length with the tail – 120 to 163 mm (4.7 to 6.4 in) – 5.5 inches – How many SGMs go into the tail of the legendary Mouse of Minsk, the famed creature spoken about in An American Tale? – 11,520 mice.

Weight with the tail – 1.5 to 2 ounces (40 to 60 grams) – 1.7 ounces average – How many SGMs go into the approximate weight of Mickey Mouse (60 pounds)? 565 mice.

Average litter size – 2.6 pinkies – How many average SGM litters go into the largest puppy litter in ever (24 puppies)? Hint: They were neapolitan mastiffs born to a mother named Abellatino Arabella. 9.2 litters.

Major Fact

Southern grasshopper mice have a high pain tolerance and resistance to stings.

Their favorite meal it the Arizona bark scorpion. The most venomous scorpion in North America. Can cause severe pain, numbness, vomiting lasting up to 72 hours in humans

Enough to kill most mice with ease and debilitate large predators. The mouse turns the scorpion’s venom into an ally. They have a protein in their nervous system that binds to the toxin.

When the mouse is stung, it instantly feels the hot pain of the venom in the sting sight. Scorpions sting repeatedly in close succession. The mouse takes a pause to rub and lick the sting sites. After a few seconds the toxin binds to the protein. It stops hurting and takes on a new effect as an analgesic. That’s right, the scorpion’s venom is now acting as a pain-killer

Why? Strap in. It’s about to get sciency. Pain neurons have a three channels that need to open for a mammal to feel pain. Venom trips two channels, one which acts as a pain gatekeeper, and another that sends pain signals to the brain. However, in the mouse, the second gate has these amino acid proteins different than other mammals. They bind to the toxin and stop it from triggering the broadcasting gate. That explains the painlessness but not the immunity. There’s more to a toxin than pain. It should cause damage. We have no idea why the mouse doesn’t just die a painless death.

This protein has given scientists ideas about more specialized pain relief medications with fewer adverse effects.


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