Are Woolly Bear Caterpillars Poisonous? Toxicity Explained

Woolly caterpillars are cuddly, and lots of people want to keep them as pets. But one question always comes up – are woolly bear caterpillars poisonous, like many others are? Let’s put all the fears at rest once and for all.

Caterpillars often make an appearance in kids’ storybooks as friendly worms. Yes, these insects are usually not aggressive and do not bite humans.

However, they are certainly not always something to be played with. In fact, some of the caterpillars can be so dangerous and poisonous that they can kill humans.

In this article, we will discuss the woolly bear caterpillar and find out if they are poisonous to humans and pets.

What Are Woolly Bear Caterpillars?

Woolly bears are caterpillars that grow up to be tiger moths. These caterpillars have fine and dense hair all over their bodies.

There are around eight or more types of caterpillar species in the United States that have such hair on their bodies and can be called woolly bears.

They are also known as banded woolly bears, fuzzy caterpillars, and more. These insects have black-colored bodies with rusty bands in the middle.

You can spot them in different regions of the U.S., southern Canada, and Mexico.

The chance of an encounter with a woolly bear caterpillar is highest during autumn, which is when they leave the food plants and shift into warmer spots to hibernate throughout the winter.

Are They Poisonous?

Wolly bears are not poisonous, and they are mostly harmless to people. These insects are not even aggressive, and they usually curl up like a ball to play dead when they feel threatened.

They lack a stinger and do not bite. However, if you touch them without any protection, there is a chance that the stinging hairs on their body can break into your skin, causing irritation and pain.

Other Poisonous Caterpillars

While the woolly bears are not poisonous, there are many other venomous caterpillars that can be lethal for humans. Here are a few of them:

Buck Moth

These caterpillars can grow up to 2 inches in length. They have a blackish-purple bodied topped with some bright yellow spots. Buck moth bodies are filled with sharp spikes that are harmful. You are likely most encounter them during the mid-summer season in willow trees.

Io Moth

Io moth caterpillars are green to yellow in color and have a red line bordering their body. They also can grow up to 2 inches in length and have black spikes all over the body. They usually eat plants like roses, corn, elm, oak, apple, clover, and more.

Puss Caterpillar

They show an average growth of an inch. A Puss caterpillar has a wooly coat of brown hair beneath which you will find a bunch of poisonous spikes that can cause problems like severe irritation in humans. You will find them feeding on trees like apples, maple, oak, and more.

Slug caterpillars

Slug caterpillars get their name from the habit of crawling around in leaves like a slug. If you look at them from above, you won’t be able to spot the head and legs. You are most likely to spot them crawling around leaves during the late summer.

Do They Bite or Sting?

Wolly caterpillars don’t have a stinger which is why they don’t bite humans. On top of that, they are not aggressive; if they feel threatened, they will curl up like a ball to play dead.

Do They Harm Humans or Pets in any way?

Although these insects don’t bite humans or pets since they are covered with fine hair, touching them without proper precautions can cause problems. The hair is strong enough to break past the human and cause severe irritation. Also, if your pet swallows one of these, the hair can get stuck in the throat, which will cause problems like allergies, gagging, coughing, and more.

Are They Dangerous to Plants?

The woolly bear caterpillars often feed on garden plants, flowers, and shrubbery.

They chew out big holes in these plants, and if a big group of caterpillar attack one plant, they can damage it to quite an extent.

On top of that, when they eat these plants, it decreases the aesthetic value of the garden flowers.

What Do They Turn Into?

The woolly bear caterpillar grows up to become an Isabella moth or a Giant Leopard moth, which is considered the largest tiger moth in the east. You will be surprised to know that it can take around 14 years for the eggs to turn into a complete moth for these species.

How Do They Survive Winters?

To survive the cold temperature in winter, the woolly bears search for warm places like rocks, fallen logs, and more to crawl into. They spend the entire winter hibernating in such spots.

There is folklore according to which these insects can be helpful in forecasting the weather.

If the brown band in their bodies is wide, there will be a comfortable and mild winter. However, if it is a completely black caterpillar, the upcoming winter will be harsh.

Frequently Asked Questions

Wrap Up

Woolly bear caterpillars are harmless to humans, but one should never try to handle these creatures recklessly.

The hair present in the body can cause problems like severe irritation. Also, if your pet swallows one, it will encounter problems like coughing and gagging.

Therefore always be cautious around these caterpillars. Thank you for reading the article.