At last each has made her choice. The work of construction begins; and my expectations are fulfilled far beyond my wishes. The Osmiae build nests in all the retreats which I have placed at their disposal. The glass tubes, which I cover with a sheet of paper to produce the shade and mystery favourable to concentrated toil, do wonderfully well. All, from first to last, are occupied. The Osmiae quarrel for the possession of these crystal palaces, hitherto unknown to their race. The reeds and the paper tubes likewise do wonderfully. The number provided is too small; and I hasten to increase it. Snail-shells are recognized as excellent abodes, though deprived of the shelter of the stone-heap; old Chalicodoma-nests, down to those of the Chalicodoma of the Shrubs (Cf. "The Mason-bees": chapters 4 and 10.--Translator's Note.), whose cells are so small, are eagerly occupied. The late-comers, finding nothing else free, go and settle in the locks of my table-drawers. There are daring ones who make their way into half-open boxes containing ends of glass tubes in which I have stored my most recent acquisitions: grubs, pupae and cocoons of all kinds, whose evolution I wished to study. Whenever these receptacles have an atom of free space, they claim the right to build there, whereas I formally oppose the claim. I hardly reckoned on such a success, which obliges me to put some order into the invasion with which I am threatened. I seal up the locks, I shut my boxes, I close my various receptacles for old nests, in short I remove from the building-yard any retreat of which I do not approve. And now, O my Osmiae, I leave you a free field! The work begins with a thorough spring-cleaning of the home. Remnants of cocoons, dirt consisting of spoilt honey, bits of plaster from broken partitions, remains of dried Mollusc at the bottom of a shell: these and much other insanitary refuse must first of all disappear. Violently the Osmia tugs at the offending object and tears it out; and then off she goes, in a desperate hurry, to dispose of it far away from the study. They are all alike, these ardent sweepers: in their excessive zeal, they fear lest they should block up the place with a speck of dust which they might drop in front of the new house. The glass tubes, which I myself have rinsed under the tap, are not exempt from a scrupulous cleaning. The Osmia dusts them, brushes them thoroughly with her tarsi and then sweeps them out backwards. What does she pick up? Not a thing. It makes no difference: as a conscientious housewife, she gives the place a touch of the broom nevertheless.