The town of Hostalric, in La Selva, has been suffering for a week from a fly plague that fills the municipality and is complicating the lives of its residents. Some businesses in the municipality have been forced to close for a few days because it is impossible for them to go to work: shops, bars, and restaurants cannot operate, and those who can open do so with the inconvenience of having dozens of these insects around.

In nature there are several examples of animals impostors They manage to fool their predators thanks to their physical appearance. As their names indicate, the bee fly and the ant spider pretend to be what they are not in order to survive: the first earns respect with its colors and the second appears to be harmless. However, research confirms that one of the queens of mimicry would be the blue fly. According to a study led by the Institute of Evolutionary Biology (IBE), the larvae of this insect are capable of developing a "mask" and a characteristic smell to coexist with termites.