This story was originally published on HackerNoon at: https://hackernoon.com/the-mother-decides-the-sex-of-the-egg. The remnants of the cocoon are also thrown away, but not always, for the delicate silken wrapper sometimes adheres closely to the masonry. Check more stories related to science at: https://hackernoon.com/c/science. You can also check exclusive content about #science, #non-fiction, #hackernoon-books, #project-gutenberg, #books, #jean-henri-fabre, #ebooks, #bramble-bees-and-others, and more. This story was written by: @jeanhenrifabre. Learn more about this writer by checking @jeanhenrifabre's about page, and for more stories, please visit hackernoon.com. I will begin with the Mason-bee of the Pebbles. (This is the same insect as the Mason-bee of the Walls. Cf. "The Mason-bees": passim.—Translator's Note.) The old nests are often used, when they are in good enough repair. Early in the season the mothers quarrel fiercely over them; and, when one of the Bees has taken possession of the coveted dome, she drives any stranger away from it. The old house is far from being a ruin, only it is perforated with as many holes as it once had occupants. The work of restoration is no great matter. The heap of earth due to the destruction of the lid by the outgoing tenant is taken out of the cell and flung away at a distance, atom by atom. The remnants of the cocoon are also thrown away, but not always, for the delicate silken wrapper sometimes adheres closely to the masonry.