I love watching caterpillars turn into butterflies! I grow a lot of dill and carrots in my garden, so I get Black Swallowtails ovipositing (laying eggs) on those plants every summer. To make sure the caterpillars safely turn into butterflies, I bring them inside as soon as I find them. Here's what I've written so far about my adventures with caterpillars, including how you could try it yourself.
Did you know Black Swallowtail Caterpillars only eat plants in the carrot family? Dill, carrots, fennel, & Queen Anne's Lace.