Dilly the Swallowtail Caterpillar

"Mommy we have a new pet!" Recently my kids came home from an afternoon at their grandparents' house with a tiny caterpillar. It was called Dilly, as they were found in Gram's dill, and brought to our house because my youngest child was very interested in having a bug as a pet and my mom knew I'd be into that sort of thing. And so began our journey into the world of raising a swallowtail caterpillar!

We put Dilly on some sprigs of fennel and dill, which were placed in a mason jar full of water. We quickly realized we needed a cardboard box underneath, as Dilly was basically a caterpillar poop machine. We put Dilly right where we'd place a vase of flowers, and everyone in the family enjoyed watching them munch their way through the fennel. (See the picture above for Dilly's funny backbend way of eating!)

After about 2 days, Dilly got really still, and stayed that way for about 12 hours. I was a little worried they were dead! But Dilly was just shedding their skin. And then they ate the skin. Waste not, want not, I suppose. The newer and improved Dilly continued their munching for a few more days. Then one afternoon my spouse pulled me into the kitchen and whispers, "DILLY IS MISSING!" It turns out swallowtail caterpillars are very content to stay on their food source– until it's time to form a chrysalis. And then they go a little wild, and start crawling all over to find the right place. We searched all around, and Dilly had actually escaped to our porch through a little crack in the screen door. We scooped it back up, and I went about creating a makeshift habitat.


swallowtail caterpillar

Makeshift swallowtail habitat


Reader, I have never felt so crafty as when I created this home for Dilly. I ran outside and grabbed a few small sticks my kids had collected. I found a small box to anchor the sticks. And then I grabbed a meshy reusable produce bag to keep Dilly in one place. I used a little duct tape to keep the bag in place.

Dilly crawled manically all around the habitat. A few hours later, they settled into one spot, and stayed there for about 24 hours. One night, before I sent to bed, I went to check on them. Dilly was doing some strange wiggling motions, almost as if it looked like it was going to throw up. Then, Dilly started using it's legs to shed it's skin, revealing the chrysalis. It was so fascinating, and honestly, a tiny bit gross!

Dilly the chrysalis stayed that way for about 10 days, and then one morning the chrysalis looked much darker. Hatching time was near! I moved Dilly's habitat right next to my computer so I could see them hatch. At one point I looked up from my work, didn't see the chrysalis, and there was Dilly the black swallowtail butterfly!


swallowtail caterpillar

Dilly the black swallowtail butterfly


It was time to return Dilly to the wild. I removed the mesh produce bag, put them on the porch, and after a few hours, off flew Dilly the butterfly. There are lots of sites on how to raise swallowtail butterflies, and I encourage you to read more if you want to do this at home. But really, it was great fun, and everyone in our family immensely enjoyed the up-close view of Dilly's transformation.

For videos of Dilly as both a caterpillar and a freshly hatched butterfly, check out our Instagram!

Do you want to attract swallowtails to your garden? We've got a growing guide to attract swallowtails!

Beth Saunders