The form and arrangement of the incisor and molar cusps on the mandibles of grasshoppers varies according to the typo of food they eat and is largely independent of the taxonomic position of the species. As the grasshoppers get older their mandibles become worn and the original cusps may be completely worn away. It is possible that this may have some effect on the ability of the grasshoppers to feed, but laboratory experiments suggest that the effect is not sufficiently great to be a significant factor causing mortality.