Solution:

The causes of arthropods, which constitute up the largest group of animal kingdoms, are listed below.

(i) They have jointed legs, which enable them to move about and perform a variety of different duties.

(ii) Their bodies are protected by a chitin skeleton.

(iii) Hard skeletons help the body retain water.

(iv) Show a new locomotion, breathing, and reproductive system.

(v) The ability to live in a variety of environments and ecosystems.

(vi) They are pre-developed in compared to other phyla.

(vii) A well-developed nerve system and sense organs.

(vii) Some insects have pheromones that allow them to communicate.