How do you use a dichotomous key to identify an animal?

athropods do have 5 main groups called crustaceans,archanids,cetipedes,millpiedesand insect.

athropods are invertebrates with the following general charaterstics:

They have jointed legs,

They have segmented bodies.

They have hard outer coverings known as exoskeletons which they shed from time to time as they grows.