Males have a wingspread of about 1 inch while the females are wingless. They arch their back into a loop, anchor the hind legs and extend the front to move ahead. Larvae grow to 1 inch, are variable in color and marked predominantly with green, brown and pale yellow longitudinal stripes. There are many other species of inchworms many of these are cryptically colored. Inchworms may sometimes be confused with loopers which are in the family Noctuidae.
Most adult Geometridae have winged females.
Wings may be rounded or highly irregular is shape, and dull to brightly colored. Moths in this family often hold their wings together over the back like a butterfly at rest. Females can only migrate by walking because they are wingless. Females crawl up the tree trunks and onto branches to lay eggs in clusters of about 100 in bark crevices or on the limbs. The eggs of spring cankerworms hatch in a few weeks while the eggs of the fall cankerworm remain from November until March or April.