The larvae or caterpillars are the first stage in the life cycle after hatching. Caterpillars, are "characteristic larvae with cylindrical bodies, short thoracic legs, and abdominal prolegs (pseudopods)". They have a sclerotized head capsule with an adfrontal suture formed by medial fusion of the sclerites, mandibles (mouthparts) for chewing, and a soft tubular, segmented body, that may have hair-like or other projections, three pairs of true legs, and additional prolegs (up to five pairs). The body consists of thirteen segments, of which three are thoracic and ten are abdominal. Most larvae are herbivores, but a few are carnivores (some eat ants or other caterpillars) and detritivores.