Bumblebees begin their adult lives by eating their sisters’ faeces. After many months as helpless, hungry larvae, they spin a silken cocoon and transform their bodies. When they emerge, ready to face the world, they get mouthfuls of poo.  It may not sound like an auspicious start, but it’s essential. The faeces contain special bacteria that act as part of the bee’s immune system, protecting it from an incredibly dangerous parasite.

Different species carry their own unique microbiota. The social bees, both honey and bumble, have a distinctive set that consists of surprisingly few species. These bacteria aren’t found in solitary bees, so they seem to be tied to communal living.

Bumblebee larvae have their own gut bacteria, but as