When this little repast is over, the labourer returns to his work, and his body and feet repeat the same motions as before.[AO] Before they can commence building, however, when a colony or swarm migrates from the original hive to a new situation, it is necessary first to collect propolis, with which every chink and cranny in the place where they mean to build may be carefully stopped up; and secondly, that a quantity of wax be secreted by the wax-workers to form the requisite cells. The secretion of wax, it would appear, goes on best when the bees are in a state of repose; and the wax-workers, accordingly, suspend themselves in the interior in an extended cluster, like the curtain which is composed of a series of intertwined festoons or garlands, crossing each other in all directions--the uppermost bee maintaining its position by laying hold of the roof with its fore legs, and the succeeding one by laying hold of the hind legs of the first. [Illustration: Curtain of Wax-workers secreting wax.] "A person," says Réaumur, "must have been born devoid of curiosity not to take interest in the investigation of such wonderful proceedings." Yet Réaumur himself seems not to have understood that the bees suspended themselves in this manner to secrete wax, but merely, as he imagined, to recruit themselves by rest for renewing their labours. The bees composing the festooned curtain are individually motionless; but this curtain is, notwithstanding, kept moving by the proceedings in the interior; for the nurse-bees never form any portion of it, and continue their activity--a distinction with which Réaumur was unacquainted.