Here are dorsal and ventral views of a caterpillar collected on our driveway last fall. I believe this is a species of Datana possibly D. perspicua, the Spotted Datana. The adult moth is a drab brown. The top view shows its segmented body, its black and yellow stripes, and its sparse bristles.
Caterpillars are insects and, as such, have six legs arranged in three pairs. The true legs can be seen in the lower photograph toward the head end of the caterpillar on the right. Each is tipped with a black claw. However, toward the middle this caterpillar has four other pairs of leg-like structures. These are the prolegs, and they help the caterpillar creep about. They are not present in the adult moth.
Always wondered how that worked, but not enough to remember to look it up or ask you! Thanks!