What Do Woolly Bear Caterpillars Eat? Helpful Tips

Planning to keep a woolly bear as a pet but don’t have the answer to “what do woolly bear caterpillars eat?” Don’t worry; all the information is just a scroll away.

As harmless as it is small, a woolly bear is not actually a bear but a small caterpillar. They were named so by James Edward Smith, a botanist, and curator of insects. 

James named them after their fuzzy appearance and interesting fur pattern with bands of black, brown, and black on their backs. 

These fuzzy, harmless caterpillars are found in abundance all throughout the American continent, including the US, colder areas of Canada, and warmer Mexico.  

What Do Woolly Bear Caterpillars Eat

You can often find them feeding on garden plants, ivy, plantain, dandelions, clover, nettles, and other such shrubberies. 

In this article, we learn more about what these caterpillars eat and the proper care they need to survive in captivity.

What Is a Woolly Bear Caterpillar?

It is the juvenile stage of the Isabella tiger moth (Pyrrharctia Isabella).

Woolly bears can be distinctly identified from other caterpillars by their fur, which is brown and capped by black at the ends. 

Their body is formed of 13 segments, but if threatened, they curl into a uniform, round ball and play dead. 

There runs a tale that the colors of woolly bears signify the severity of the coming winter season based on how much of their bodies are brown and black. A more brown caterpillar signifies a mild winter. 

However, these are all myths. In fact, their color depends on how large the caterpillar is and its age. 

Moreover, there is a wide variety of these creepy crawly’s, with nearly 260 species being found in North America alone. 

Each has its own coloring pattern, so it is hard to tell anything by its color alone. As an adult moth, they have a wingspan of 1 ½  to 2 inches with black dots on them. 

Woolly Bear

Yellow Woolly Bear Caterpillar Diet

Woolly bears are a generalist species that can survive on a wide variety of native plants. Their dietary preference is very varied. They snack on almost any leaf and can survive without water. 

Woolly caterpillars are herbivorous and feed on fruit trees, herbs, grass, grains, nettles, and more. 

They are more inclined to leafy plants (as opposed to those with blades) such as goldenrod, dandelion, spinach, clover, and cabbage. 

Mostly, they feed on low, ground-dwelling plants. They show minor interest in fruits but have been known to, on occasion, feed on sunflowers. 

Among trees, they prefer elms and maples. They are also known to ingest poisonous plants like foxglove! 

In the adult form, isabella tiger moths mainly survive on nectar from flowers and survive only a week. 

What To Feed Them As a Pet?

Due to their non-toxic nature, woolly bears make great pets for kids. They are also available aplenty all across the US. 

As a pet, make sure you give them a fresh and new leaf pile every day. This includes leaves such as those of lambs’ quarters, violets, and clovers.

If you have a garden, you can store and feed them weeds such as ground ivy, plantain, and dandelions. 

Woolly Bear Caterpillar

For grass, make sure you give them the young, fleshy grass instead of the mature grass, which has turned into blades. 

Apart from feeding, once your pet woolly bear is ready to form a fuzzy cocoon, make sure you give them appropriate barks and branches to hang from. 

Do woolly bear caterpillars need water?

Woolly bears do not drink water. They source their water from the plant content they eat. 

Hence, if you keep one as a pet, you can simply mist the container from time to time instead of setting out a separate petri dish for water. 

How long can woolly bear caterpillars go without food? 

In caterpillar form, wooly bears are aggressive eaters and eat for months. However, once in the cocoon stage, they go into a chrysalis and stay without food for the entire duration. 

During these few months, they will not eat anything at all. 

In general, we know that caterpillars cannot survive without food for too long, and some, like the Monarch caterpillar, enter can starve in as little as 24 hours. 

What Eats Wooly Bear Caterpillars?

The thick hair helps these caterpillars survive some of their predators, such as yellow jacket wasps. 

However, common predators include mantids, flies, and birds such as the American crows, thrashers, and towhees and catbirds. 

As an adult, their main predators are bats and spiders. Despite this, woolly bears are aplenty, and their global conservation status is rated as G5. 

This means that they are not declining in numbers and are existing across multiple localities healthily. 

Woolly Bears

Frequently Asked Questions

How do you keep a wooly bear caterpillar alive?

It’s best to keep a woolly bear in a well-ventilated jar with plenty of fresh, misted leaves. 
Make sure to give them a dark space to hide in as well. Before going into a cocoon, give them a branch to cling to. 

How long do woolly worms live?

In a warm climate, the caterpillar stage lasts only two weeks, after which they enter into a pupa. 
In cold areas, they use their dense fur to freeze themselves (by controlling the temperature of their body) and pupate after winter. In short summers, the caterpillar stage may even last years. 

Is it safe to hold a woolly bear caterpillar?

Woolly bears are completely safe to hold, despite their bristly and spiky appearance. 
However, their hairs may cause allergic reactions in people with sensitive skin and irritation in pets (if they happen to eat the wooly bear). 
Usually, on being touched, they pretend to be dead and turn into a coil. 

How can you tell how old a wooly bear caterpillar is?

A woolly bear will molt six times over the course of its caterpillar stage. After every molt, more brown hairs are added. 
Hence, by seeing how long the brown patch is, one can gauge how long it has been alive. 

Wrap Up 

Woolly bears have been long been a fascination among children. In fact, Ohio even holds a Woollybear Festival every Fall where everyone dresses up as these caterpillars. 

If you’re planning on keeping a woolly bear as a pet, make sure you give them a diet full of juicy, soft leaves and mist their tank every day.

Thank you for reading. 

Reader Emails

Over the years, many of our readers who decided to try their hand at keeping these cute and cuddly woolly bears as pets asked us all about their diet and what to feed them.

Learn all about their experiences; it might help you in your own quest to keep them in your home.

Letter 1 – Eyed Tiger Moth Caterpillar

 

black bristly caterpillar Photo attached. This was found in Austin, Texas, walking near the handle of our patio door. He is predominantly black, bristly, with a brownish red head and three orange/red bands around the back end. Since he is lifting his front end, there may be more red bands, hard to tell. In terms of scale, this fellow is +/- 1.5 inches long. The hole in the picture is ~1/8th inch in diameter. THe nearby environment is a large flower garden filled with butterfly and hummingbird attracting plants (designed that way). Common medium-large butterflies in the garden recently include: * various swallowtails (giant, pipevine, tiger) * gulf fritillary * hackberry spp. * red admirals (not all that often) * hummingbird clearwing moth I’m familiar with these caterpillars, and this ain’t one of ’em. We also have commas/question marks. Is this one of them? We have many smaller butterflies (e.g. texas crescent, common hairstreak, fiery skipper) but I figure this guy isn’t a candidate for them, since he’s good sized. Hard to find a good site of caterpillar pictures. THanks, Jim Hi Jim, The caterpillar of Ecpantheria deflorata, the Eyed Tiger Moth, “is a deep black, clothed with black hairs, and at the junction of the somites, or segments of the body, it is banded with rings of crimson” according to Holland. Sounds like your caterpillar. The moth is found in your area and the caterpillar, one of the wooley bears, feeds on plantain, pr Plantago. We have a photo of the adult moth on our homepage right now. Here is a nice caterpillar identification site.

Letter 2 – Silver Spotted Tiger Moth Caterpillar

 

Silver-spotted Tiger Moth Caterpillar June 4, 2010 It’s been raining all morning and there was finally a break so I step out on the porch only to see this fuzzy little guy. It looks like he’s having a bad hair day (it must be the humidity) with all the gunk stuck on him. I tried to find him on your site but could not. However, after looking at bugguide (http://bugguide.net/node/view/43315) I think he is a silver-spotted tiger moth caterpillar. I live on the outskirts of Portland, Oregon surrounded by forests with lots of Douglas Firs so I am sure he is well fed. I notice bugguide says not to touch them due to venomous hairs…I wish I would have known that before but I think I will survive! I believe I have him IDed but wanted to share him with you. Amy Portland, Oregon, USA
Silver Spotted Tiger Moth Caterpillar
Hi Amy, Thanks for sending us a photo of what we agree is probably a Silver Spotted Tiger Moth Caterpillar, Lophocampa argentata.

Letter 3 – Tiger Moth: Orange Holomelina or Ruddy Holomelina???

 

Orange Holomelina rubicundaria – Virbia rubicundaria Location:  Lexington NC August 16, 2010 10:38 am I think this is an orange Holomelina rubicundaria – Virbia rubicundaria moth. He was very small, and though he was orange, blended in rather well. He was not too cooperative, but i I didn’t give up till I had at least one good shot of him. Rick (SCWIDVICIOUS)
Tiger Moth: Orange Holomenlina
Hi again Rick, Again we must state that we love getting insects that have been preidentified because then we just try to find links that support the identification.  We checked out Virbia rubicundaria on BugGuide and the Moth Photographers Group, and we must say that we believe its close relative in the same genus, Virbia aurantiaca, looks like another possibility.  See both BugGuide and The Moth Photographers Group to compare.  In this case, the opinion of a real expert might be required.  Since this is a Tiger Moth, we will see if our friend the Arctiid expert Julian Donahue can provide a conclusive ID. Great, I hope we get a verdict from Julian. I know its a rather strange angle that could possibly hinder the ID, but it’s all he was willing to do for me.  I have loads of insects I plan on sending your way, and I will try to ID each one of them as best I can. I love your site, it helps a lot of people in a lot of ways, and  I have spent countless hours looking around, which is one reason I like to contribute what I can. My insect  photo collection is huge, and i try to take the best photos I can with my crappy lens. When I can finally land the lens i really want, you will see some beautiful pics coming your way for sure. Thanks Rick, for both the compliment and the contributions, especially of new species for us like this Holomelina.  Since we teach photography we feel qualified to say we did not notice the crappy quality of your lens.  We think your photos are perfectly fine.  Trust us when we say we get plenty of blurry photographs of enormous size that take copious amounts of post production time before a mediocre image can be posted.  The photo is only as good as the person behind the camera and as long as the equipment provides a usable image, it is more than adequate. Julian Donahue provides information, but no conclusive identification August 17, 2010 Hi Daniel, According to Covell’s eastern moth book, rubicundaria is a Gulf Coast species, while aurantiaca would be the one from North Carolina. However, I wouldn’t bet on either one–I don’t have Zaspel & Weller’s 2006 revision of Virbia (including the former Holomelina) at hand. This is a tough group, and even spread specimens are sometimes difficult to identify. Julian P. Donahu

Letter 4 – Garden Tiger Moth Caterpillar

 

Brown hairy caterpillar id Location: Halifax, Nova Scotia, Canada June 24, 2011 4:35 pm Long brown hairs, about 3-4cm long. Thought it might be a Garden Tiger Moth. Spotted June 20, 2011 Halifax, Nova Scotia, Canada Signature: Wildlife & Plant Sightings, junponline.com
Black Woolly Bear
Dear Wildlife and Plant Sightings, We agree with your identification, but we would like to provide some clarification according to BugGuide.  Since the species Arctia caja is found in Europe as well as North America, the common name differs in the new world and old world.  The Garden Tiger Moth is known as the Great Tiger Moth in North America.  The caterpillar is simply a Woolly Bear in Europe, but in North America it is called the Black Woolly Bear to distinguish it from other Tiger Moth Caterpillars.

Letter 5 – Unexpected Cycnia: Metamorphosis of a Tiger Moth

 

Cycnia Inopinatus – larva/pupa/adult, 1 of 2 Location: Naperville, IL August 22, 2011 12:32 pm Dear Daniel~ I found this little caterpillar on August 10th, on some asclepias tuberosa (butterfly weed). I tentatively ID’ed it as Cycnia Inopinatus, but I’d read that although it might be locally common, overall it is uncommon to rare due to habitat decline. It was certainly the larva of a tiger moth, and its coloration, host plant and region (Great Lakes area) all pointed to the unexpected tiger moth. I placed it in one of my Monarch egg-rearing containers for observation, but before long, and before I could move it, it made its cocoon and pupated on the container’s lid. (Sorry for the red color cast.) It eclosed this morning, and sure enough, it’s a beautiful little cycnia inopinatus, similar in its adult stage to the delicate cycnia moth (cycnia tenera) that you have on your site, but whose larvae are quite different. The photos of the adult are in a separate submission, and I’ve included a side view so that you can see its orange, speckled abdom en. All the best to you! Signature: Dori Eldridge
Unexpected Cycnia Caterpillar
Cycnia Inopinatus – larva/pupa/adult, 2 of 2 Location: Naperville, IL August 22, 2011 12:40 pm Dear Daniel~ Here are the three adult photos of the cycnia inopinatus (unexpected tiger moth) that eclosed this morning. The second photo shows his (?) antennae, which were previously tucked under the body. It flew away before I could get a better side view! Best regards, Signature: Dori Eldridge
Unexpected Cycnia Cocoon
Hi Dori, Thank you so much for providing our website with such a thorough documentation of the metamorphosis of the Unexpected Cycnia, Cycnia inopinatus, a new species of Tiger Moth for our website.  We are most intrigued with the number of creatures that depend upon milkweed for survival.  Readers who want additional information can see the postings for this species on BugGuide.
Unexpected Cycnia Moth
Ed. Note:  July 11, 2014 More information on the Unexpected Cycnia can be found on this blog:  http://cycnia.tumblr.com/  

Letter 6 – Tiger Moth from South Africa is Speckled Footman

 

Subject: Moth Location: Johannesburg, south africa April 3, 2016 12:38 pm Hi Found this moth this morning 9am in Johannesburg south Africa. It’s Autumn here at the moment and the weather is moderately warm with temps in degrees Celsius of about 27. We live in a housing complex with a small garden and pets. The moth was on my net curtain and when I moved the curtain he headed outside into the garden. Signature: Brigitte
Speckled Footman
Speckled Footman
Dear Brigitte, Just last week we posted an image of a dead individual of this species of Tiger Moth in the genus Utetheisa from South Africa, and today we realized that the common name on iSpot is the very appropriate Speckled Footman, Utetheisa pulchella.

Letter 7 – Tiger Moth from Thailand

 

Subject: striped moth Location: northern thailand March 11, 2017 6:55 pm found this moth at night…about 2 inches across. It looks like a tiger moth or maybe a wasp mimicking moth? Something else? ? Thanks! Signature: ash
Tiger Moth
Dear Ash, We agree that this is a member of the group of Tiger Moths known as Wasp Moths.  We have found several similar looking images online.  There is a similarity between your individual and this moth identified as Amata sperbius that is posted to FlickR, but we believe a closer match is this image identified as Syntomoides imaon also on FlickR.  Here is another member of the genus also pictured on FlickR.

Letter 8 – Probably Tiger Moth Caterpillar from Guatemala

 

Subject: What kind of caterpillar is it? Location: San Martin Jilotepeque, Guatemala April 8, 2017 10:03 am Hello Mr. Bugman! my brother is living in Guatemala, San Martín Jilotepeque. Yesterday he found this pretty caterpillar and adopted it in his house. I think it could not be a brilliant idea, but anyway we would like to know what is it. 🙂 Could you help us? It was eating coffea frond. Thank you so much! Signature: Belén Zuazúa de Loresecha
Tiger Moth Caterpillar
Dear Belen, We are pretty sure this is a Tiger Moth Caterpillar in the subfamily Arctiinae.  In North America, they are commonly called Woolly Bears.

Letter 9 – Tiger Moth from Thailand

 

Subject: Is it Yponomeutidae?. Location: Pho Prathap Chang, Pichit, Thailand April 16, 2017 1:24 am Hi, I found this little moth in my grandmother’s house on April 14 around 11.00am. – 12.00pm. Location neither southern north nor northen central. I wonder whats its common name is because I very love insects including Lepidoptera. I will share more of moths and butterflies pictures because I caught some catterpillars and pet it and release it in to the nature. sorry for language. Signature: Focus Tharatorn Neamphan
Tiger Moth: Utetheisa pulchelloides
Dear Focus, This is NOT an Ermine Moth in the family Yponomeutidae.  It is a Tiger Moth in the genus Utetheisa, probably Utetheisa pulchelloides which we located on the Farangs Gone Wild site and the Butterfly House site where it states:  “The species occurs widely in the Indo-Australian region, including : Borneo, Cook Islands, New Zealand, Thailand, and much of Australia.”  

28 thoughts on “What Do Woolly Bear Caterpillars Eat? Helpful Tips”

  1. Is it typical of woolly bear pupae to have that sparse hair-like cocoon? I saw something stuck to the inside of one of our umbrellas that looked awfully similar. Hopefully I can get some decent pictures of it tomorrow.

    Reply
    • Woolly Bear Caterpillars shed their hairs and incorporate the hairs in the spinning of the cocoons. It is often possible to see the pupa through a thinly spun cocoon.

      Reply
  2. im 13 and i study bugs and i noticed this site when i was looking for more info however that is not a silver spotted tiger moth cause 1 off it is no venomous 2 off it has no read but it could be a relative of one

    -Daniel

    Reply
  3. im 13 and i study bugs and i noticed this site when i was looking for more info however that is not a silver spotted tiger moth cause 1 off it is no venomous 2 off it has no read but it could be a relative of one

    -Daniel

    Reply
    • We maintain that the image of the caterpillar of a Silver Spotted Tiger Moth, Lophocampa argentata, that is posted to BugGuide matches the individual pictured in this posting. BugGuide also states: “Note of Caution: Like several kinds of wooly-bear-type caterpillars, these have venomous, stinging hairs, which can cause a burning sensation and/or a rash in sensitive people- look, but don’t touch!”

      Reply
  4. i have studyed these guys for almost a month now.And have held multiple specimons and they are
    most certainly not poisounis

    Reply
    • I agree with u I have raised 1 before and 3 right now 4 in total and not once have I had issues like poison if they were they would attack us with those hairs right away as soon as they crawl on our finger they are not poisonous or I’d be dead right now from touching 4 or more of them

      Reply
  5. i have studyed these guys for almost a month now.And have held multiple specimons and they are
    most certainly not poisounis

    Reply
  6. does anyone know what the moths eat? I, like Daniel, am a teen who likes to raise them. I don’t know if they are like some other species of moths, and don’t eat anything, or if they actually have a food source.

    ~safire

    Reply
  7. does anyone know what the moths eat? I, like Daniel, am a teen who likes to raise them. I don’t know if they are like some other species of moths, and don’t eat anything, or if they actually have a food source.

    ~safire

    Reply
  8. They are poisonous, but it only effects sensitive people. I too have been handling them all my life, and have not been effected in any way. That doesn’t mean the experts are wrong. It simply means that I am not sensitive to the hairs.

    I had two of my cocoons hatch, and I am happy to say that I now have two dozen eggs.

    Reply
  9. They are poisonous, but it only effects sensitive people. I too have been handling them all my life, and have not been effected in any way. That doesn’t mean the experts are wrong. It simply means that I am not sensitive to the hairs.

    I had two of my cocoons hatch, and I am happy to say that I now have two dozen eggs.

    Reply
  10. I happened to find a silver spotted tiger moths caterpillar a month and a half ago and within 12 hours of having it, it started pupation. Does anyone know how long it usually takes before it emerges as a moth? I’m worried that the little guy didn’t make it.

    Reply
    • According to BugGuide, caterpillars feed on “Douglas Fir (Pseudotsuga menziesi) but not uncommon on other conifers. There are also a few reports of them eating a wide variety of other plants.”

      Reply
  11. I don’t beleave ppl who say it’s poisonous I have raised 4 or more and had them crawl on my hand and not once felt what ppl say u feel and I never got a rash and I’m one person who has sensitive skin and I would be dead by now with how much I hold them each day so I don’t beleave a word some of u say

    Reply
  12. I’ve been collecting these caterpillars for a week or two, feeding them to see what the cocoons will look like. (I had no reaction to gently scooping them up in my hand.)
    Yesterday I finally found a cocoon in their container–with an obliging caterpillar modeling adjacent to the cocoon.
    Coos Bay, Oregon, USA
    (I’d post a photo if I could remember how to do that… Guidance?)

    Reply
  13. I’ve been collecting these caterpillars for a week or two, feeding them to see what the cocoons will look like. (I had no reaction to gently scooping them up in my hand.)
    Yesterday I finally found a cocoon in their container–with an obliging caterpillar modeling adjacent to the cocoon.
    Coos Bay, Oregon, USA
    (I’d post a photo if I could remember how to do that… Guidance?)

    Reply
  14. I have held many of them no rash or anything like that. from my research from other sources the “venom” or hairs only hurt those with sensitive skin.

    Reply

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