 Social animals need an alarm system to alert others to defend against potential threats or to recruit others to attack prey.In "Eciton burchellii", along with other large-colony ant species, the alarm pheromone is produced in mandible glands.This is evolutionarily advantageous because the mandible has a large surface area for pheromone's evaporation, the pheromone is released whenever the mandible is opened for biting, and the pheromone is rapidly released when the ant's head is crushed.