Do Wooly Bear Caterpillars Help Predict Weather?

A wooly bear caterpillar is black at both ends of its body and has one reddish brown stripe in the middle.

A wooly bear caterpillar turns into an Isia Isabella Moth like the one above.

 The wooly bear caterpillar, which turns into the tiger moth, Isia Isabella, is the source of a common superstition. Some people believe that the coat of a wooly bear caterpillar can be used to predict how bad the coming winter will be. There are many wooly bear caterpillars in the United States and Canada. They can be seen anytime from May to October.

They believe that if a wooly bear caterpillar's brown stripe is thick, the winter weather will be mild and if the brown stripes are narrow, the winter will be severe.

One experiment showed that the color bands might tell where the caterpillar grew up. Some think that the wide black bands mean the caterpillar was living in wet conditions while the wide brown band means the caterpillar was living in dry conditions.

The coloration may also show how near being an adult the caterpillar is. At full growth, fall weather signals the wooly caterpillar to seek shelter, as ladybugs do.

In the late 1600s, farmers relied on weather history to predict weather. For that reason, they looked for something in nature to help them. They found the wooly bear caterpillar. Reports about the weather, along with a comparison of wooly bear stripes, made people think that the wooly bear's coat was a good signal about weather. Some people still believe the wooly bear caterpillar can be used to predict weather.

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