No description or size or location given, but wandering usually means they are looking for a place to pupate. Without a picture or good description and location there is no way to identify it to species, and so no way to suggest what plants this species normally eats. But if its a true wooly bear, ie an Arctiidea or so called Tiger Moth, common dandelions are acepted as an alternate larvel food plant by most species of that family.

Hi Shannon! My daughter and I raised our first black wooly bear this summer. We researched online to find out what they eat and they seem to eat a variety of plants. We fed ours maple leaves and dandelion. He hung out in our cage for about a week before he formed his cocoon. I couldn't tell he had eaten very much, and his cocoon didn't look like it formed properly. I thought he was dead, but I kept checking on him. About 3 or 4 weeks later, I went out one morning and there was this beautiful Giant Leopard Moth in the cage. We were thrilled! He was white with metallic blue/gray spots. Gorgeous! We opened the cage but he didn't fly away. After two days I moved him to the outside of the cage, and by that afternoon he had flown.

By all means, try raising one, but be careful not to touch the cat with your bare hands. Many hairy caterpillars have a toxin that transmits into your skin when you touch the hairs. The hairs scratch your skin and this transmits the toxin.

The woolly bears (woolly is often mis-spelled) do not have the toxin mentioned above, and have been commonly handled by people. It is said that some people may be allergic or sensitive to the bristles. Very young children may not be able to discern between woolly bears or other toxic caterpillars.

It is common to see these caterpillars wandering around in the fall months. They are looking for a place to hibernate through the winter months. They won't form a cocoon or pupae until next spring. After they wake up in the spring, they will continue to eat for a short while and then they pupate. As Larry mentioned, Dandelion is a favored food. They pupate for approximately 2 weeks. The adult moths are like silk moths in that they do not have mouth parts, so do not nectar or feed. Their sole purpose is to procreate. If your caterpillar is black, it is probably a Giant Leopard Moth, or Ecpantheria scribonia, but coloration can be variable.

I've attached a link to Bill Oehlke's information on raising them. Have fun!

Susan

Here is a link that might be useful: Raising a Wooly Bear