The Coordination of Locusts

Locust swarms find direction from an unusual cue - microbes. Researchers have found that bacteria that live within locusts, symbionts, synthesize a chemical called guaiacol. That chemical is an integral part of a pheromone, a molecule made by an organism that can go airborne and signal to other members of that organism's species.

After a fertile period, there may be an explosion in a population of locusts, which have to be able to sense when an area is getting overcrowded. One way they can do so is by detecting the pheromones made by the symbiotic bacteria. Learn more from the video by I Contain Multitudes, a feature from Howard Hughes Medical Institute.