It is Sphinx atropo time, again. I have observed during any clear nights, that this big moth "sings" like a queen, while is going into the hive to rob the honey.
Here, a poetic paragrahp about the reason of this song used by the moth as password.
"Upon the workers this royal cry has a magical effect. It terrifies them, it induces a kind of respectful stupor; and when the queen sends it forth, as she halts in front of the cells whose approach is denied her, the guardians who have but this moment been hustling her, pushing her back, will at once desist, and wait, with bent head, till the cry shall have ceased to resound. Indeed, some believe that it is thanks to the prestige of this cry, which the Sphinx Atropos imitates, that the latter is able to enter the hive, and gorge itself with honey, without the least molestation on the part of the bees. "
This one will not sing any more.