Grasshoppers are insects, commonly compared to katydids or crickets. The main difference between these groups is that grasshoppers generally have shorter antennae than the length of their bodies. Scientifically speaking, grasshoppers are in the order Orthoptera, with a suborder of Caelifera. These insects have a huge range of habitat, and predominantly feed on grasses with their sharp, strong mandibles. Many species of grasshopper make clearly audible noise by rubbing their back legs against their wings or abdomen.