Posted by lin korpinska on December 28, 2005

Q: Hello, I have been researching wooly bears for a while, as I am currently taking care of one. However, I have one problem that seems to contridict what I have read, and wonder if I am doing something wrong. At a Christmas tree farm this December I found a wooly bear lying in the snow, so grabbed him up and brought him home. The temperature outside must have been approx. 20¬?F at night when we found him. Not wanting to change his environment, we put him in the refrigerator which is set to around the same temperature. I would think that by know he would have become completely dormant, but each time I check on him he has crawled to a different spot (i.e. he is in a cup with a little bit of curned up paper towel to hide in) Should I feed him or give him moisture? Is it okay that he is still crawling around? I have had him almost for a month. I hope he will make it to spring. What is in optimal spot to put him in the spring? Near clovers in the grass? In a tree?

Habitat: forest/open woods

State: Massachusetts

Habitat: forest/open woods

A: You're going to know more about Woolly Bears than almost anyone else by next spring - I applaud your interest in this animal. I received your second question too and think your caterpillar is probably alright even though not crawling around. As with any animal or plant, if you think in terms of "what this animal would be doing in a natural environment", it will make decisions on care both easier and more accurate.

To begin with, your caterpillar is not interested in food anymore. Woolly Bears feed all summer but in the fall find a location in which they can be dormant until spring while they live off of the fat in their bodies. In the spring, they change into the pupal phase (a cocoon-like structure) and then emerge as an adult moth some time later. So, no food for your bear! I haven't tried to care for a Woolly Bear myself, but keeping it in the refrigerator might work for a while, but I wonder if it isn't too warm for the entire winter! You mentioned finding your guy in the snow when days were in the 20's. Freezing temperatures shouldn't be a problem - all of those other Woolly Bears are outside right now. I think I'd place your guy in a container that he can't escape from that allows good air flow and then place him in an unheated garage. Be sure no mice can get to him or they may eat him. The garage temp will vary over the winter and at times even be below freezing but this will approximate his dormancy in the wild. Keep an eye on him and in the early spring, watch him a bit more closely. At some point, he should pupate and then he'll develop into a moth but I don't know how many days this will take. I would be careful about one other variable though. Daylength may be an important part of your guy's dormancy and may "tell" him when to pupate. In other words, as days lengthen, something in his body may tell him, now is the time to move into another phase of life. If this is the case, your bear will need access to daylight in his container - don't keep him in darkness.

I've given you a lot of information but can't tell you for sure since few people have ever tried this. But as I said earlier, this should give you a real understanding for these interesting animals. Keep in mind too that your animal may not live - in nature, many don't make it for one reason or another. My very best to you and I'd love to hear how this works out. Feel free to write to me again if you have more questions and I'll do my best.

John Wiessinger ( December 29, 2005)