Mating is serious business for rattlers. They go miles looking for females. They have to fight other males on the way. The fight is a wrestling match, and the loser suffers severe psychological damage. He loses his will.
Females test an approaching male by taking the male fight pose.
Only winners dare to claim their prize. It really is a case where only the brave deserve the fair. Pit vipers are far more advanced than other snakes. They're equipped with spare teeth. Their forked tongue is an enormously sensitive scent sensor.