I was leading a field trip through a botanically diverse fen, when we encountered two of our showiest wetland caterpillar species just feet apart. The top one is a Smeared Dagger Moth caterpillar, and the other is a Henry's Marsh Moth caterpillar. We temporarily moved the latter into the proximity of the former for photos, then returned it to its original plant. When working with caterpillars, it is always critical to return them to the plant that they were feeding on, if they are temporarily detained or moved.