Grasshoppers are insects that can hop, walk, and fly. Many male grasshoppers make noise by rubbing their back legs together. There are about 10,000 different species of grasshoppers. Like all insects, the grasshoppers have a three-part body (head, thorax and abdomen), six jointed legs, two pairs of wings, and two antennae. Their body is covered with a hard exoskeleton. Grasshoppers breathe through a series of holes called spiracles; they are located along the sides of the body. Most grasshoppers are green, brown, or olive-green. The biggest ones are about 4.5 inches (11.5 cm) long.
Grasshoppers are around in the spring and summer, but are most noticeable in the autumn. Areas with many grasses, small "vacant" lots and gardens are good places to start looking. Look at the area as you walk through. If you can hear the plants moving as you walk there are most likely grasshoppers around. Look during the middle of the day for best results. At night, use a flashlight to find grasshoppers roosting on the leaves. In the summer and autumn, some grasshoppers fly into porch lights.
*******The following is from http://en.wikipedia.org/wiki/Grasshopper**********
Grasshoppers are herbivorous insects of the suborder Caelifera in the order Orthoptera. To distinguish them from bush crickets or katydids, they are sometimes referred to as short-horned grasshoppers. Species that change colour and behaviour at high population densities are called locusts.