Today’s Wonder of the Day was inspired by Makenna. Makenna Wonders, “Does the color of caterpillars predict what sort of winter we will have?” Thanks for WONDERing with us, Makenna!

Is it going to be a harsh winter? Or will it be mild? How can you tell?

Do you rely on the almanac? Or do you turn to woolly worms?

For many, many years, legend has held that woolly worms can predict whether the coming winter will be mild or harsh. Is there any truth to this belief? Or is it an old wives' tale?

Woolly worms are actually the larval stage of the Isabella tiger moth (Pyrrharctia Isabella). They are known by various names, including woolly bear caterpillars, banded woolly bears, fuzzy bears, and black-ended bears.

Woolly worms get their name from their fuzzy appearance. They have black bands at each end with a red-brown band in the middle.

Each autumn, woolly bear caterpillars take shelter under leaves and other low-lying vegetation. In the spring, they complete their transformation into Isabella tiger moths.

People who believe woolly worms can predict the weather think that a narrow red-brown band means a harsh winter. The wider the red-brown band is, the milder the coming winter is supposed to be.

There are several towns in the United States that hold annual woolly worm festivals each fall. In addition to caterpillar races, these festivals also usually feature an official declaration of the woolly worm's prediction for the coming winter.

But how accurate are woolly worms at predicting the weather? As it turns out, they're not so accurate.

Scientists who have tested woolly worms' predictions have found that there is no correlation between woolly worms' bands and winter weather. Instead, they note that the color and size of a woolly worm's bands are likely affected by several factors, including availability of food, conditions during development, age, and species.

Woolly worms aren't the only creatures that people look to for information about the weather, though. Here are some of the other animals and insects that people believe have weather-predicting abilities:

  • Groundhogs: Each February 2, Americans wait for groundhog Punxsutawney Phil to predict whether we will have six more weeks of winter or an early spring. Unfortunately, the National Climatic Data Center claims that Phil has only correctly predicted the weather about 39 percent of the time.
  • Frogs: Some people believe that frogs croak louder and longer than normal when bad weather is on the way.
  • Birds: How high are the birds in the sky? This is the question some people ask themselves. They believe that high-flying birds signal clear weather, and low-flying birds mean a storm is headed your way.
  • Bees: If you notice that the bees buzzing around your flowers have suddenly gone missing, you can bet that bad weather may be on the way.
  • Ladybugs: As the old saying goes, “When the ladybugs swarm, expect a day that's warm." On the other hand, if they're looking for shelter, cold weather is on its way.
  • Ants: If you notice ants building up their mounds for extra protection or even covering the mounds' holes, you might want to prepare for some rain!

Can all of these animals and insects successfully predict the weather? Not always!

However, scientists do believe that many animals and insects have heightened senses that allow them to predict when certain types of weather are imminent. Confirm with the weatherman, but pay attention when you see animals and insects behaving in strange ways!

Wonder What's Next?

Ready to think outside the box? Come celebrate Boxing Day…Wonderopolis-style!