I photographed this Inchworm at Piney Falls when we stopped to eat lunch. It was very active so I had a bit of trouble catching it in this position. An inchworm is the larva of a group of moths called Geometer Moths. Geo-meter means "Earth-measurer". These caterpillars loop or inch their way along because of the number and placement of their prolegs. They don't have prolegs all along their abdomen, just at the end. So, when they move forward with their 6 true legs on the thorax they have to pull their prolegs forward to catch up.