Be thankful today’s rodents are small

Be thankful today’s rodents are small

Photo by Alexas_Fotos on Unsplash

Originally published 21 October 2003

I’m not feel­ing very friend­ly toward rodents right now. I have mice in the pantry and squir­rels in the attic.

The mice are tak­ing advan­tage of my kind­ly nature. Do they know that I set the traps reluc­tant­ly, not wish­ing to see their adorable Mick­ey Mouse eyes look­ing up accus­ing­ly from beneath the sprung bar? “I may be dead,” they seem to say, “but you are the mur­der­er. I mere­ly stole some crack­er crumbs.”

The squir­rels are a big­ger prob­lem. I killed a squir­rel once, when I was 12 years old, with my uncle’s “bor­rowed” .22, and vowed I would nev­er do it again. So now I’m risk­ing life and limb on a tall lad­der try­ing to secure their means of ingress to the attic. I wish I had their head for heights.

I’m guess­ing that you aren’t par­tic­u­lar­ly fond of rodents, either. Rats give the whole order of rodents a bad name. Not even the chirpy cute­ness of chip­munks can erase the mem­o­ry of the Black Death, a dis­ease that was car­ried by rats.

Still, rats and all, the rodents are a suc­cess­ful clan. They are the largest sin­gle group of mam­mals, about 1,500 species alto­geth­er, includ­ing mice, rats, squir­rels, chip­munks, ham­sters, guinea pigs, beavers, muskrats, por­cu­pines, and prairie dogs. They live on every con­ti­nent except Antarctica.

It’s not a par­tic­u­lar­ly use­ful bunch of ani­mals, from a human point of view, which no doubt suits the rodents fine. A few rodents make ade­quate pets, if you don’t mind hear­ing the squeak of ham­ster wheels all night long. I’ve heard that rodents are used for food in cer­tain parts of the world, but muskrat steaks don’t strike me as par­tic­u­lar­ly yummy.

Chin­chillas are rodents, so the folks who wear furs have some­thing to like. And it would be remiss of me not to men­tion the mil­lions of mice and rats that have lived and died in the ser­vice of sci­ence as exper­i­men­tal animals.

Of course, oth­er crea­tures did not evolve for our ben­e­fit; after all, humans are pret­ty much late­com­ers on the scene. We are prob­a­bly more use­ful to rodents than they are to us. Con­sid­er how glee­ful­ly squir­rels have adapt­ed to our back­yard bird feed­ers, and mice to our kitchens. Human homes and gar­dens are a roden­t’s idea of par­adise — warm shel­ter, food aplen­ty — and just try to keep them out.

What dis­tin­guish­es rodents from oth­er mam­mals is a sin­gle pair of incisors in each jaw, nifty gnaw­ers beau­ti­ful­ly adapt­ed for chew­ing through the fas­cia boards of hous­es, say, or crack­er box­es in the pantry. These teeth are heav­i­ly enam­eled on the front but not on the back, which means they stay chis­el-sharp as they wear down. And they nev­er stop growing.

The biggest liv­ing rodent is the semi-aquat­ic capy­bara of South Amer­i­ca, which is about the size of a sheep and looks rather like a small, fur­ry hip­po. And now comes word that we missed the biggest rodent of all — by about 8 mil­lion years.

Pale­on­tol­o­gists recent­ly found in Venezuela the fos­sil remains of an extinct rodent, called Phoberomys, that was the size of a buf­fa­lo and resem­bled a giant guinea pig. It has been whim­si­cal­ly dubbed Guineazil­la by its discoverers.

Why did it go extinct? Maybe big, slow-mov­ing rodents were easy prey for big­ger, faster ani­mals, say some pale­on­tol­o­gists, which begs the ques­tion of why big, slow-mov­ing rodents evolved in the first place.

Phoberomys bal­anced on its tail when stand­ing on its hind legs, and could pret­ty much have looked you in the eye. Imag­ine a herd of these mam­moth, buck-toothed chew­ing machines descend­ing on your gar­den. Be grate­ful you only have white-tailed deer and rab­bits to con­tend with.

And, by the way, speak­ing of buck teeth, rab­bits aren’t rodents. They belong to an order called Lago­mor­pha that may or may not be close­ly relat­ed to the Roden­tia. Rab­bits, hares, and pikas — the Lago­morphs — have an extra pair of gnaw­ing teeth in the upper jaw. If rab­bits could climb trees and run tele­phone wires, I sup­pose I’d have them in my attic, too.

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