Black swallowtail caterpillar
I have two of these swallowtail mfunciacaterpillars eating the tops of my carrots. Is this normal for this late in the year? Is there a way for me to help them get through their process so the frost wont kill them?
It is best to just let them do their thing... which is eat.
It's not terribly late, and once they fatten up they will crawl away and make their chysalis. Depending on when that is, they will hatch out again within a week or two, or they will 'pause' and hatch out as butterflies next spring.
They don't need our help, other than to manage our gardens and landscapes in the least toxic ways possible, and perhaps to plant their favorite foods.