Inchworms

Instead of inchworms, you may use the term loopers or spanworms; however, each refers to caterpillars that do not have appendages under their mid-sections and move by grasping with their front legs and then drawing the back legs to that point and creating the image of a loop. Next, the front legs release and attach to a new location while the back legs follow.  This process continues as the larvae of the Geometer moths seem to "measure the earth" as they move.  Have a look!