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Woolly Bear Caterpillar

Summary: Banded woolly bears are the larvae of the Isabella tiger moth. It is fuzzy and harmless, unlike other hairy varieties.

The Isabella tiger moth's fuzzy looking caterpillars are known as banded woolly bears. Your kids have probably picked them up and played with them, but there is little to fear. They are harmless, unlike some other hairy species.

The woolly bear caterpillar has black bands on both ends of their body and red, orange, or brown centers. As superstition goes, if as woolly bear's black bands are long, the coming winter will have harsh weather. However, the length of their black coloration actually depends on the amount of moisture they receive.

Should you pick up the banded woolly bear it will curl up and play dead. The solitary banded woolly bear is usually seen scurrying about on its own, as it does not like to congregate with its fellow woolly bear cousins.

The banded woolly bear eats grass and different types of plants. It overwinters in stacks of firewood or underneath bark or logs. Like most other caterpillars, it forms a chrysalis to begin pupation and remains there for three or four weeks. Some woolly bears go through metamorphosis in the summer, while others overwinter and pupate in the spring.

The adult that emerges from the cocoon of the banded woolly bear is the Isabella tiger moth which as a wingspan of up to 2 ½ inches. Their wings are typically yellow or brown, with black spots. Female Isabella tiger moths lay their eggs on several different types of plants, including sunflowers and corn. Isabella tiger moths have a unique trait that other insects do not have. They can emit a sound to ward off their predators.


Woolly bears are a big deal in Vermilion, Ohio (a rural area west of Cleveland). The city dedicates an entire day of celebration to woolly bears at their annual Woolly Bear Festival. The small, one-stoplight town of Banner Elk, North Carolina also hosts a Woolly Worm Festival. They have a woolly worm race with over 1,400 racing caterpillars. The winner of the race is the banded woolly bear that will predict the severity of weather of the coming winter. Other woolly bear festivals include Beattyville, Kentucky every October and the Camargo, Illinois festival, complete with woolly worm races and reports from local meteorologists.

Many people enjoy raising banded woolly bears before they develop into moths. Here are some tips on how to do this. Before collecting the woolly bears, find an appropriate container to store them. A small plastic container with a lid should work just fine. Make sure to poke some holes into the lid for ventilation.

Add some soil into the container to allow the caterpillars to burrow. Feed the woolly bears crumbled pieces of leaves or other plants. They actually enjoy eating dandelions, so you will have a good use for your weeds. Make sure to add a small amount of water once every two weeks or so. Do not over-water the soil, though.

When fall comes around, the woolly bears will become slow moving. This is their cue for them to overwinter. If you want to raise them into moths, keep them in a cool environment, such as a garage or a basement.

To raise them as moths, you will need a place to store them. You can create an emergence cage for them to live in as they grow. Take some old window screens and cut them so that they are about 8 inches high. Find two used tuna cans (make sure that the edges are filed smooth so you do not cut your fingers. Make a cylinder with the screen and staple the ends together. Place one tuna can on the top and one on the bottom of the cylinder. Now you have your emergence cage.

Put about 2 inches of soil inside the cage, as well as plenty of leaf debris for the woolly bears to munch on. Put one or two woolly bears in the cage and watch them develop into Isabella tiger moths.

If you want to catch adult Isabella tiger moths, keep in mind that they are attracted to light in the nighttime. If you hang a white sheet or tablecloth over a clothesline outside and place a light source behind it, you may be able to attract the moths.


Jeff Sandoz
17 Mar 2013, 14:03
What are the natural enemies of the Wooly Caterpillar? How does it fend these off by sound?
Joanne Bedard
23 Mar 2013, 18:39
Just wanted to know, I live in Ottawa Canada, it's March 23, cold, and we have lots of snow, for the first time ever, I just found what I just found out is a Wooly Caterpillar. Now I've seen them in the fall before, and yes they do predict the winter, but never found one this early in the spring, and he was just walking across my path I brought him in and put him in a jar with celeri leaves and a few twigs...just wondering if this is a rare occurence or not...thanks!!
Jaime Leisure
02 Apr 2013, 20:06
@ Joanne
I live in Alaska and I also found a wolly caterpillar late March. found mine on the 30th, I brought him in and gave him some romaine lettuce and this morning woke to find him spinning his chrysalis!
22 May 2013, 01:47
I was googled to this page because I was looking for the recommended extermination process for these caterpillars, not how to love, house, raise, or where to find them. John if you found the expert let me know.
12 Sep 2013, 11:11
if the cocoons dont hatch after 3 to four weeks with spotted tussock (wooly caterpillar) then maybe try and freeze it for a few day to make it think its gone through winter, it wont die by freezing it has a antifreeze that will allow it to withstand -6c to -8c
24 Oct 2013, 21:11
My catapillar got lost in the house when I acsidently threw him..... his name was Leo.... never got to see the 3 day home with me. Do they eat fabric because mom is going to flip if they do...... Im sad.
24 Oct 2013, 21:18
How come their face looks like their butt? @Lucy good question I know they eat it when they grow up and stuff but not really catapillars just greens right?????????
29 Dec 2013, 14:19
I live in Michigan. I came across two Wolly Caterpillars today. They were located about 15 miles from each other. One in Holly and the other Flint. Yesterday the temp was 46 and today it's 36. We're just getting over a ice storm where the temps were well below freezing. Is it normal to see these caterpillars in December in michigan?
25 Apr 2014, 21:48
I found two wooly bear cater pillars but one escaped out of a box I could not find him and the box is still full there is no hole what could have happend
20 Jun 2014, 19:30
How do I irradiate black woolly caterpillars from the trees in my yard. I don't want to raise them, I want to kill them as my wife is TERRIFIED of them. I'm not sure of what type of trees I have( maybe pecan&firmosa) either way, I don't want my wife constantly afraid to go in the back or front yard. Please HELP, desperately seeking solution(s).
25 Aug 2014, 09:51
@Peggy: Why do they need to be exterminated. Like he said, they're harmless. If nature is leaving you alone, leave IT alone.

@Eric: Your wife needs to grow up. You don't kill animals that are perfectly harmless to you because they "look scary".
24 Nov 2014, 14:38
Does the bite from one of these contain poison
15 Dec 2014, 18:34
It is December 15th 2014 and I found a wooly bear today! I was so sad because he could have died. I live in a 3floor house each floor is an apartment and my down stairs neighbors almost ran him over. I brought him up to my apartment put him in a jar with some leaves . He is very active. I just love him!
14 Jan 2015, 16:37
Our Wooly Bear caterpillar has hatched into the moth in the dead of winter. What can we do to help it survive until spring?
Mandy w
22 Jan 2015, 19:21
Hi everyone. My wooly worm did the same thing as Cindy's. It just started to cacoon I was trying to see if there is anything I can do to help him go into hibernation or not. Also if we should give him a mist if water in his cacoon?
We figure we will let him grow and turn into a moth and fly around the house. To cold out to put him out. And they don't have teeth so he can't eat anything. I read it's a one to two week life span. I feel bad it won't have a mate since it's winter but at least he wasn't bird food, I guess.
26 Jan 2015, 14:10
I have 4 woolly bears. I started my "project" when I found a little black one by my apartment door. 145 days later, yesterday it made its cocoon. The others are black and orange and 2 of those are still hibernating. They will most likely not moth at the same time and they only have a couple days to find a mate. I'll set them free as each turns. Hopefully, they'll find more moths out there if it's not too cold. It's been a fun project.
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