What the woolly worm told me

By Lyndsie Kiebert-Carey
Reader Staff

Everyone knows about the prognosticating powers of the groundhog, recognized each February when Punxutawney Phil does or does not see his shadow, indicating the remaining length of winter. The ritual is generally accepted as more playful than prophetic. This is especially true in North Idaho, where the only predictive species I’ve ever heard taken seriously is the woolly bear caterpillar.

Woolly bears — or woolly worms, as they are often called in the southern and eastern states — are the small, fuzzy, black-and-rust-colored wigglers that pop up in large numbers seemingly out of nowhere in the chilly sunshine of North Idaho autumns. They are actually not worms at all, but the larva of the Isabella tiger moth. Woolly caterpillars are found in most of North America; and, despite what people call them, there seems to be general agreement about their singular ability to predict the harshness of the upcoming winter.

The basic guidelines are these: the wider the rust-colored band on the woolly bear, the milder the winter; the more black coloration on the insect, the more snow is headed your way.

There are, of course, variations on these standards. For instance, finding out which way the caterpillar is going might provide a more specific prediction, with the black band near the head foreshadowing the beginning of the winter and the tail end predicting the season’s severity closer to spring.

This has been the talk of the playground at the elementary school where I work (where the woolly bears have names and special caterpillar-sized habitats built for them), as well as at my husband’s job, where one of his coworkers recently claimed to have seen a mostly black woolly bear, foreshadowing a brutal winter.

Count me among the people predicting the worst for North Idaho this snowy season, as I recently came across my own woolly bear without a speck of orange to be seen.

On my way out the door, walking across the driveway to my car, I nearly stepped on him. All-black, fuzzy as can be and wiggling his way across the gravel with a real sense of purpose.

I had no doubt that Mr. Woolly Bear had some place to be — probably somewhere cozy, like my garden shed or firewood pile, in preparation for the hellish onslaught of cold to come. 

I carried this encounter with me for a few weeks before bothering to learn more about the old wives’ tale of the woolly bear caterpillar. I had somehow placed this superstition in the oral-history category of my brain: a place where things simply are, without question, a reality because they always have been.

Living in the age of the internet, I decided to learn more.

It isn’t clear when the legend of the prognosticating woolly bear originated, but it was first well-documented as a possible scientific phenomenon in the late 1940s by American Museum of Natural History Curator of Insects and Spiders Dr. C. Howard Curran. A 1948 excerpt from Time magazine documented Curran’s quest to log the width of the caterpillar’s orange bands and compare the data to the following winters. 

Over nearly a decade, the evidence was largely inconclusive because of the study’s small size. Still, the resulting publicity launched the folksy tradition to new notoriety. To this day, towns — mostly in the South and East — hold festivals based on the woolly bear (or worm) and its ability to predict the coming winter.

It is through this research that I learned something particularly pertinent to my recent experience: woolly bears can’t be entirely black. If you find one, many of my sources noted, it’s not a sign of an apocalyptic winter on the horizon. Rather, you’ve simply come across a caterpillar belonging to a different moth species.

In the spirit of scientific integrity, I concede that none of us will predict the winter, no matter the tools — insectoid or otherwise — at our disposal. But out of a sense of loyalty to the oral-history side of my brain, I can’t help but believing that Mr. Woolly Bear — in all his fuzzy, black-as-night glory — actually was a woolly bear caterpillar, and he was trying to tell me something.

I’ll make sure we have an extra cord of firewood, just in case.