When the team found the larvae in Morocco, they were occupying the termite mound’s food chambers. Once in the laboratory, they observed that the fly larvae tended to settle in the most populated areas of the nest, where they received constant attention from the termites, which preened them using their mouthparts.

Although the team was unable to reveal their diet, they were able to observe trophallaxis-like behavior: the termites appeared to transmit food to the larvae using their mouths. “The larvae are not only tolerated, but they constantly communicate with the termites through contact with their antenna-like tentacles. The termites even seem to feed them, although this has not yet been unequivocally demonstrated,” explains Vila.

The team stresses the difficulty of keeping these insects in the laboratory, as it involves maintaining colonies of desert termites, which live in very special conditions. “The larvae we studied eventually died without metamorphosing, so there may be elements of the nest and the symbiotic relationship between the termites and the flies that we were unable to transfer to the laboratory. Their diet is currently unknown, and their adult form remains a mystery,” adds Vila.