Arthropods in Reverse

Arthropods are vertebrates in reverse.
Insect mouths mammalian anuses,
An interesting fact that sounds perverse,
Exoskeletons that act as trusses
To interior muscles and organs
Form different fulcrums to vertebrate
Skeletons, interior structures suns
Cannot shed light on before our end-fate.
Our social species are even different,
Especially in our altruisms –
Vertebrates became more independent,
Arthropods have suicidalisms.
Two opposite species practically
Aliens to each other, fatefully.