How Did Weasels Get Such a Bad Rap?

least weasel
The least weasel (Mustela nivalis) is a species of weasel with a maximum length of just 8.5 inches (21.7 centimeters) and an average weight of a meager 1.9 ounces (55 grams). Yann Guichaoua-Photos/Getty Images

It's time to admit we've done weasels wrong. Sneaks, cutthroats and liars aren't called "lions" or "opossums" in English-speaking societies. Nope; these unsavory characters get branded as "weasels." We've also managed to turn the word "weasel" into a verb — and not the fun kind. To "weasel your way out" of something is to deceitfully avoid it.

Anti-weasel sentiments extend far beyond linguistics. In "Zootopia," "The Wind in the Willows" and "Who Framed Roger Rabbit?,"the tubular mammals play sleazy bad guys. And long before those storied movies came along, weasels were deemed bad omens in ancient Greece. Some of their image problems harken back to common misconceptions. Others have more nuanced roots.


Little Creatures, Big Appetites

Weasels are nimble, long-bodied mammalian predators that belong to the genus Mustela. Most species hail from Eurasia and the Americas. There's also an African critter with skunk-like markings that's often called a weasel, even though it represents a different genus.

By popular definition, weasels tend to be smaller and more streamlined than the closely related ferrets and polecats. The biggest species — like the North American long-tailed weasel (Mustela frenata) — can measure up to 16.5 inches (42 centimeters) long from nose tip to tail tip. Others rival Beanie Babies in size. The aptly named "least weasel" (Mustela nivalis) has a maximum length of just 8.5 inches (21.7 centimeters) and its average weight is a meager 1.9 ounces (55 grams).


One thing they've all got in common is their sky-high metabolic rates. Unlike bears, weasels can't depend on long-term fat reserves. Burrowing rodents are dietary cornerstones for most of these animals. In order to chase their victims down narrow tunnels, weasels evolved with small, thin and short-furred bodies.

But there were some trade-offs. Because staying lean is a matter of survival, weasels don't put on a lot of body fat. And without thick fur coats, they struggle to retain body heat. So to meet their energy needs — and stay warm — weasels burn a lot of fuel. This forces them to process meals very rapidly. As such, many species must consume 20 to 40 percent of their body weight in food every single day!

When they're not nabbing rodents, weasels will eat rabbits, birds, reptiles, amphibians and various invertebrates. If you ever get the chance to watch one of the fuzzballs go hunting, take it. You might be in for quite a show.


Dramatic Diners

Photographer Martin Le-May captured the snapshot of a lifetime back in 2015. While exploring an English park, he witnessed a least weasel riding around on the back of an airborne woodpecker. His amazing pictures of this encounter quickly went viral.

This wasn't an inter-species joyride; it was an attempt at predation. Evidently, the weasel attacked the bird while it was grounded, setting of an aerial rodeo. Le-May's woodpecker managed to escape, but other birds aren't so lucky. Even predatory raptors can fall victim to the ferocity of weasels. From time to time, eagles and buzzards swoop down and snatch the mammals, hoping to score a quick meal. That can backfire if the weasel reaches up and bites its captor on the neck or chest. Sometimes, the weasel manages to not only survive the skirmish, but also turn the tables and devour its would-be attacker. And sometimes, both parties die. C'est la vie.


Poultry is great, but so are omelets. Among chicken farmers, weasels are notorious for killing prized birds and making off with their eggs. Therein lies a popular misconception. The short-tailed weasel (Mustela erminea) will put a small hole into an egg and then lap up the contents as they come oozing out.

What they don't do is actively suck out the yolks and the whites, like some kind of breakfast food vampire. Nevertheless, the belief that weasels suck eggs has lingered for centuries. William Shakespeare referenced it in "Henry V." Comparing England to an eagle, a worried character says, "To her unguarded nest, the weasel comes sneaking, and so sucks her princely eggs."

Theodore Roosevelt helped spread the myth. "When a weasel sucks eggs the meat is sucked out of the egg," claimed the ex-president at a 1916 speech. The image of an empty eggshell reminded Roosevelt of the hollow, vague and toothless language favored by many politicians. Some of TR's contemporaries used to call this kind of meaningless rhetoric "weasel words." Roosevelt liked the phrase and helped to popularize it.

In so doing, he reinforced the stigmatization of actual weasels.


Of Mustela and Men

We can't blame Shakespeare and Roosevelt for all of the Mustela genus's PR problems. Historically, weasels have often found themselves at odds with chicken farmers. The svelte creatures can slip into chicken coops through unprotected holes in the wall. Once inside, they can raid nests — or attack the birds themselves. Most weasels prefer rodents to chickens, which means they can actually benefit chicken breeders by ridding the premises of vermin. Nevertheless, weasels will hunt fowl if the chance arises.

So it's no wonder why lots of farmers came to see weasels as sneaky, devious creatures. Furthermore, as time went by, the carnivores were branded as murderers of an especially vicious and bloodthirsty sort. You see, due to their high metabolisms, weasels will often wrangle more food than they can eat in a single sitting.


The extra grub is stored in cache sites, such as abandoned animal burrows. One of these makeshift food cabinets was found stuffed with nearly 150 dead voles that were stashed away for future meals.

From an evolutionary standpoint, that impulse to kill extra game makes perfect sense. It's also the reason why weasels have been known to slaughter every chicken in sight upon entering a coop — which does not endear them to many agricultural communities. Fortunately, there are steps chicken breeders can take to prevent these incidents from occurring.

But there are some places where weasels simply don't belong. In New Zealand, introduced least weasels are decimating native bird populations. The government is taking active steps to remove these unwelcome guests, but combating invasive species is always a difficult job.

While New Zealand's weasels are causing real harm and should be dealt with, that doesn't justify western society's centuries-long disdain for the Mustela genus as a whole. Yes, weasels are crafty little beasts with healthy appetites. That's what makes them so fascinating — and so richly important to their native ecosystems.