Looks like a moth, but I really don't know which one. Watch out, some of them sting!

Wish I could be of more help. If he is a moth though, try throwing a few things in there for him to eat, as it seems as though many moths are general feeders, not relying on one specific food source.

It's a woolly bear/Isabella tiger moth caterpillar.
'Love their coloring!
Sherry

So is it worth watching him metamorphize? I don't get a warm, fuzzy fealing when I thing of moths.

When you say general food sources, are you talking steak, corn pops, fruit, or lettuce? ;) No really.

She means that they'll eat most any type leaves from trees or low growing plants - I don't think they'd thrive on the first three things you mentioned, but they might on lettuce. Of course, the lettuce may have been treated with Bt, so it could poison the cat.
It would probably be better if you put it back where you found it and let him/her feed itself.
Sherry

My was found in spring on white sweet clover, but they will eat any clover among many other plants and tree. Since you found it this late it may be wandering to find a place to overwinter as a caterpillar or form a cocoon and emerge next spring. Mine is still in its cocoon and should emerge next spring.

I think they are beautiful moths and have attached a link to an image of the adult moth.

Susan

Thanks for the food recommendations.

I don't see the link to the adult moth in you post.

I currently have him in a sauce jar (holes in lid for air). Should I put some twigs in there so that he can cacoon?

Will he know to form a cacoon inside the warm house and wait until spring to emerge, or is yours in an outdoor habitat?

Hi, The caterpillar will probably overwinter--according to my guide, Isabella Tiger Moth cats overwinter in leaf litter or under boards and may continue feeding in the spring. If you do keep it, you might want to put some leaves, etc in the jar and keep it in the garage or some other cold place.

If you keep it where it's warm, you might upset its "clock." It's best for us novices to try to mimic the natural environmental conditions for the critter.

The major problem with overwintering caterpillars is dealing with humidity. If there's too much, that can be troublesome, and if there's too little, the caterpillars can dry up.

I'd probably just leave it where it was, but their populations are not in trouble, so if it's something you're interested in, can't hurt to try to get it through the winter, but it might not make it.

As far as food: dandelion, grass, lettuce, meadowsweet, and nettle are listed in the guide.

Here is a link that might be useful: Scroll down for picture of adult

We've decided to let the little guy go back into nature. No purpose in keeping him if he's not going to become a moth until Spring.

Is this an invasive type cat/moth? Does it multiply out of control and damage plants? If so, I'll release him away from my property.

Thanks for the help so far.

They're not invasive in my area--doubt they are in yours either...I think most of the get run over when they wander in the fall.

There's an old adage about how their stripes forecast the coming winter. Don't remember it though and not sure how credible it is.