This gorgeously coloured caterpillar was feeding on a poplar leaf. At first it was stretched out along the leaf stem, but as it became aware of me nearby, it gradually stopped feeding and began to move into this upside down pose. The head is at the bottom. The "horn" is at the rear end. On that particular day we saw about four of these caterpillars in two different locations. Some blinded sphinx caterpillars are lacking the red spots.