At last the grubs, close-watched and fed to repletion, have achieved the requisite degree of fatness; they are on the eve of being transformed into pupae. Then and not till then the cells are closed: a big clay stopper is built by the mother into the spreading mouth of the jug. Henceforth the maternal cares are over. The rest will come of itself. Hitherto we have witnessed only the peaceful details of the housekeeping. Let us go back a little and we shall be witnesses of rampant brigandage. In May, I visit my most populous village daily, at about ten o'clock in the morning, when the victualling-operations are in full swing. Seated on a low chair in the sun, with my back bent and my arms upon my knees, I watch, without moving, until dinner-time. What attracts me is a parasite, a trumpery Gnat, the bold despoiler of the Halictus. Has the jade a name? I trust so, without, however, caring to waste my time in enquiries that can have no interest for the reader. Facts clearly stated are preferable to the dry minutiae of nomenclature. Let me content myself with giving a brief description of the culprit. She is a Dipteron, or Fly, five millimetres long. (.195 inch.--Translator's Note.) Eyes, dark-red; face, white. Corselet, pearl-grey, with five rows of fine black dots, which are the roots of stiff bristles pointing backwards. Greyish belly, pale below. Black legs. She abounds in the colony under observation. Crouching in the sun, near a burrow, she waits. As soon as the Halictus arrives from her harvesting, her legs yellow with pollen, the Gnat darts forth and pursues her, keeping behind her in all the turns of her oscillating flight. At last, the Bee suddenly dives indoors. No less suddenly the other settles on the mole-hill, quite close to the entrance. Motionless, with her head turned towards the door of the house, she waits for the Bee to finish her business. The latter reappears at last and, for a few seconds, stands on the threshold, with her head and thorax outside the hole. The Gnat, on her side, does not stir. Often, they are face to face, separated by a space no wider than a finger's breadth. Neither of them shows the least excitement. The Halictus--judging, at least, by her tranquillity--takes no notice of the parasite lying in wait for her; the parasite, on the other hand, displays no fear of being punished for her audacity. She remains imperturbable, she, the dwarf, in the presence of the colossus who could crush her with one blow. In vain I watch anxiously for some sign of apprehension on either side: nothing in the Halictus points to a knowledge of the danger run by her family; nor does the Gnat betray any dread of swift retribution. Plunderer and plundered stare at each other for a moment; and that is all.