Prolegs in the body of the world’s largest moth (dark colour), the Atlas moth (Atticus atlas), support the caterpillar in hanging upside down on a twig. Meanwhile, the smaller thoracic legs can be used to help in food processing.
Photograph of an Attacus atlas caterpillar depicting the differences between the thoracic legs, which are uniramous (have one branch) and end in a single claw, and the prolegs, which are fleshy and have many crochets at the tip.