While observing beetles that can raise their abdomens and give off a defensive chemical that repels predators,an entomologist discovers a different species of beetle that also raises its abdomen but gives off no defensive chemical.What is the second beetles' defensive behaviour called? 

A)  chemical warfare 
B)  camouflage 
C)  flight mechanism 
D)  mimicry

Mimicry

The resemblance of one organism to another or to an object in its surroundings for protection, predatory, or other purposes.

Chemical Warfare

The use of toxic chemical substances as weapons in military conflicts to kill, injure, or incapacitate the enemy.

Defensive Chemical

Substances produced by organisms as a defense mechanism against predators, pathogens, or to deter competition.