1)Bilaterally symmetrical (in most cases).
2)Body has more than two cell layers, tissues and organs.
3)Body cavity a true coelom.
4)Most possesses a through straight gut with an anus (in most cases).
5)Body possesses 3 to 400+ pairs of jointed legs.
6)Body possesses an external skeleton (in most cases).
7)Body is divided in 2 or 3 sections.
8)Nervous system includes a brain and ganglia.
9)Possesses a respiratory system in the form of tracheae and spiracles (in most cases).
10)Possesses a open or lacunnar circulatory system with a simple heart, one or more arteries, and no veins, (in most cases).
11)Reproduction normally sexual and gonochoristic, but can be parthenogenetic.
12)Feed on everything.