- Southern Arizona is home to hundreds of species of inchworms, which are the larval (caterpillar) stage of moths in the Geometridae family - These caterpillars are famous for their unique looping movement and their exceptional ability to mimic twigs and plant structures to avoid desert predators - Inchworms lack prolegs in their middle section. They move by pulling their rear end forward to form a loop, then extending their front end - Many native desert species are masters of disguise ... when threatened, they stand completely stiff at an angle to look exactly like a small broken branch or twig - They generally grow up to an inch long - Desert species are typically shades of green, brown, or gray to blend into local flora