These caterpillars fascinate me. The black-eyed susan flowers seem to be full of them right now, all decorated with bits of plant matter. Most of the ones I saw were very small to tiny, but they will grow a bit bigger before they pupate.

These caterpillars will use bits of plants from various types of flowers and leaves, so that they can look very different. I have heard that they will shed old plant matter and use new bits from the next plant they crawl onto. Amazing disguise, as they look like a bit of plant debris. The adult, the moth, is a lovely emerald green.