The Order Orthoptera is composed of two groups: Ensifera and Caelifera. In general terms they are known as locusts and crickets respectively.
They are hemimetabolous insects. They undergo different stages, but they look like their parents since they are born.
If crickets and locusts are famous for something is for their ability to jump. Of the three pairs of legs only the posterior one, which is very strong, is designed for jumping. It has springs which together with the muscle accumulate the energy which is released when the insect is eyected. They use jumping as a way of escape, fight or a simple way of moving.
Another characteristic typcal of this order are the sounds produced by rubbing body parts. In crickets the stridulating mechanism is on the forewings. In locusts it may be on the wings or on the legs. Song is used in pair formation or as an indication of allarm or aggression.
A good song needs a good ear and the location of the ear also differs in locusts and crickets. The crickets' "ear" is on the frontal tibia and the locusts' on the first abdominal segment.
The more basic difference between these two groups is the length of the antennae. Crickets have more than 30 segments and locusts less than that. Roughly speaking, long antennae is a cricket, short antennae is a locust.
Ensifera's ovipositor is scimitar-like or cylindrical. It is inserted in vegetal tissues or the ground (respectively) to lay eggs. In general eggs are laid separately. Caelifera's ovipositor is short and dented. They dig a hole and introduce the ovipositor which elongates doubling almost its size thanks to specialized muscles.
