Can a Caterpillar Really Predict the Weather?

Some people will say the answer is a resounding, "Yes!"

Others will tell you the Woolly Bear (Woolybear, Woolly Worm) is just about as accurate as the Groundhog.

Here's a photo sent to us by an e-mailer named "Saint Croix:"


"Woolly Bear" is the common name for the Isabella Tiger Moth (Pyrrharctia isabella) while it's in its larval stage. They're fuzzy with black bands on the ends and an orange band in the middle (although sometimes they can be all black, too). There are also some variations that have up to 13 alternating bands of black and orange.

The folklore says if the middle, orange band is wide, we'll have a mild winter. If the black bands are bigger, it's going to be a severe winter.

Joan from Columbus writes:
"We were at Old Man's Cave today and saw only one wooly worm. It was totally black. What does that mean regarding the weather this winter???"

And Laura from Cambridge says:
"The weather was talking about woolly worms. What does it mean when they are white? What kind of weather does that mean?"

The different colorations can come from a lot of things. Not every caterpillar conforms to the norm. They're all different... just like people. Some may have more orange or more black or more than three stripes... or no stripes at all. It's also possible that you've found a wholly different fuzzy caterpillar species (there are a bunch).

The folks in Vermillion have a Woollybear Festival every autumn. And the Old Farmer's Almanac has a good article about them called "The Truth About Woolly Bears."

Have a great winter!