A beaten road, formed of calcareous boulders crushed by passing wheels into a smooth surface like paving stones, is the quarry whence Chalicodoma sicula prefers to get mortar; whether she builds on a branch, in a hedge, or under the jutting roof of some rural habitation, it is always from a neighbouring path, or a road, or the highway, that she seeks materials—indifferent to the constant passing of beasts and travellers. You should see the active bee at work when the road is dazzling white in the hot sunshine. Between the neighbouring farm where she is building and the road where the mortar is prepared, there is the deep hum of the bees perpetually crossing each other as they come and go. The air seems traversed by constant trails of smoke, so rapid and direct is their flight. Those who go carry away a pellet of mortar as big as small shot; those who come settle on the hardest and driest spots. Their whole body vibrates as they scratch with the tips of their mandibles, and rake with their forefeet to extract atoms of earth and grains of sand, which, being rolled between their teeth, become moist with saliva and unite. They work with such ardour that they will let themselves be crushed under the foot of a passer-by rather than move. Chalicodoma muraria, however, which seeks solitude, far from human habitation, is rarely seen on beaten paths; perhaps they are too distant from the places where she builds. If she can find dry earth, rich in small gravel, near the boulder chosen as the basis of her nest, she is contented. She may either make quite a new nest in a spot hitherto unoccupied, or over the cells of an old one, after repairing them. Let us consider the first case.