In August, however, I discovered a very large green, yellow and black caterpillar with gourmet taste devouring the fennel plant. Thinking about my two-year-old more than my fennel, I scooped the caterpillar up in the bug box we got as a birthday party favor and put it in the kitchen window.

For two days the thing ate and pooped up a storm. I even had to cut another sprig of fennel for it. I really hadn’t considered any long-term plans for our new household pet. I just figured that we’d enjoy him for a few days and then release him back to nature.

Imagine my horror when, on day three, I lifted my toddler up to the window to say good morning to our caterpillar only to find him shriveled up at the bottom of the box - moldy, hard and brown. I’ve KILLED it, I thought.

Of course, anybody who knows science knows that our little pet had likely metamorphosed into a pupa. But, I’d never actually seen this up close and was alarmed by the speed and, honestly, the severity of the change. He was half the size of his former self and not the same shape at all. And this was no Eric Carle cocoon either. (Apparently only moths actually make cocoons.) It more closely resembled a stumpy twig.

I had already identified the caterpillar as a black swallowtail in my Peterson’s Guide to Caterpillars, but the book said the species overwinters as a chrysalis and I hadn’t signed on for a six-month roommate situation when I took the little guy in.

We left “Twiggy” in his box on the windowsill, primarily because I wasn’t sure what to do with him. I still thought it was possible he had died. We added him to our nighttime prayers (God bless Mommy, Daddy, Sissy and Twiggy the Caterpillar) and hoped for the best.

Several weeks later I was walking by the kitchen window when something caught my eye. Closer examination of the bug box revealed that our butterfly had emerged. He was slowly opening and closing his wings, filling them with blood.

I immediately panicked about leaving him in that cramped space all day. I wasn’t sure how long he’d go after he had emerged. I imagined that after not eating for two weeks he would want some food and water. I opened the box on the front porch and left the butterfly to take wing on his own time. He hung out for several hours, long enough for me to snap some photographs and eventually flew away when nobody was watching.

Later that evening, playing with my son in the yard, a black swallowtail swooped down over our heads, and I couldn’t help but think as I watched him sample every flower in the yard that this was our pet butterfly finding his own way to say thank you, and goodbye.