Let us keep our eyes open. There is something better than the well-preserved order of the entrances. When an Halictus appears, returning from her round of the flowers, we see a sort of trap-door, which closed the house, suddenly fall and give a free passage. As soon as the new arrival has entered, the trap rises back into its place, almost level with the ground, and closes the entrance anew. The same thing happens when the insects go out. At a request from within, the trap descends, the door opens and the Bee flies away. The outlet is closed forthwith.
What can this valve be which, descending or ascending in the cylinder of the pit, after the fashion of a piston, opens and closes the house at each departure and at each arrival? It is an Halictus, who has become the portress of the establishment. With her large head, she makes an impassable barrier at the top of the entrance-hall. If any one belonging to the house wants to go in or out, she 'pulls the cord,' that is to say, she withdraws to a spot where the gallery becomes wider and leaves room for two. The other passes. She then at once returns to the orifice and blocks it with the top of her head. Motionless, ever on the look-out, she does not leave her post save to drive away importunate visitors.
Let us profit by her brief appearances outside to take a look at her. We recognize in her an Halictus similar to the others, which are now busy harvesting; but the top of her head is bald and her dress is dingy and thread-bare. All the nap is gone; and one can hardly make out the handsome stripes of red and brown which she used to have. These tattered, work-worn garments make things clear to us.
This Bee who mounts guard and performs the office of a portress at the entrance to the burrow is older than the others. She is the foundress of the establishment, the mother of the actual workers, the grandmother of the present grubs. In the springtime of her life, three months ago, she wore herself out in solitary labours. Now that her ovaries are dried up, she takes a well-earned rest. No, rest is hardly the word. She still works, she assists the household to the best of her power. Incapable of being a mother for a second time, she becomes a portress, opens the door to the members of her family and makes strangers keep their distance.
The suspicious Kid (In La Fontaine's fable, "Le Loup, la Chevre et le Chevreau."—Translator's Note.), looking through the chink, said to the Wolf:
'Show me a white foot, or I shan't open the door.'
No less suspicious, the grandmother says to each comer:
'Show me the yellow foot of an Halictus, or you won't be let in.'
None is admitted to the dwelling unless she be recognized as a member of the family.
See for yourselves. Near the burrow passes an Ant, an unscrupulous adventuress, who would not be sorry to know the meaning of the honeyed fragrance that rises from the bottom of the cellar.