Desert Locust

• The switch from the solitary to the gregarious phase is triggered by repeated physical contact on the hind legs, which sets off a surge of serotonin in the nervous system and completely changes the animal's behaviour within hours.
• A swarm can cover hundreds of square kilometres, travel more than a hundred kilometres a day and eat as much food in one day as tens of thousands of people.
• Its plagues are described in texts more than three thousand years old and still cause food emergencies in the Horn of Africa.
• It changes personality. Under normal conditions it is solitary, green and elusive; when rain concentrates the vegetation and individuals brush against one another, it transforms into the gregarious phase: it changes colour to yellow and black, becomes more active, eats more and seeks company instead of avoiding it.
• The trigger has been pinpointed precisely: repeated rubbing of the hind legs sets off a serotonin cascade that brings on the transformation in a matter of hours.
• A swarm can cover hundreds of square kilometres and contain tens of billions of individuals; a swarm of one square kilometre eats as much in a day as 35,000 people.
• The 2019-2021 plague in the Horn of Africa was the worst in decades and affected the food security of millions of people.
• They travel up to 150 km a day riding the winds, and plagues are now tracked with satellites and weather models coordinated by the FAO.
• It appears in the Book of Exodus as the eighth plague of Egypt, and locust invasions have been documented for millennia.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat & environment

Arid and semi-arid areas of Africa, the Middle East and southern Asia

Sources consulted: https://es.wikipedia.org/wiki/Schistocerca_gregaria