The swarm-maker molecule - how serotonin transforms solitary locusts into social ones

Serotonin is a chemical jack-of-all-trades. It relays messages between the cells of the brain and in doing so, controls everything from anger to sleep, body temperature to appetite. But in one insect, it is the key to Pandora's box, periodically unleashing some of the most destructive swarms on the planet. It is the chemical responsible for turning solitary desert locusts into massive plagues.