This change in behaviour is the first and critical step in changing what are essentially just large grasshoppers, living on their own in the desert to devastating swarming pests.
Locust swarms 'high' on serotonin, BBC (29.01.09)
Why a depressed locust is a good thing... for us, Channel 4 (29.01.09)
A brain chemical changes locusts from harmless grasshoppers to swarming pests, University of Cambridge (30.01.09)
Why Locusts Swarm WYNC Radio (12.03.09)