It's widely agreed that bugs could be a sustainable source of protein for humans in the future, but large-scale production is very labour intensive. As the BBC’s Katy Watson discovers, in Mexico - where there is a long bug-eating tradition - the infrastructure required for a profitable bug industry is almost non-existent. In the US though, where the idea of having insects for lunch still turns most stomachs, some farmers are adding bugs to protein bars and crushing them into powder for health-conscious Californians. Some proponents say insects could be the new sushi. But are they right? (Picture: A scorpion served up in Mexico.)