While the Andrena and Halictus bees, whose habits we now describe, are closely allied in form to the Hive bee, socially they are the "mud-sills" of bee society, ranking among the lowest forms of the family of bees. Their burrowing habits ally them with the ants, from whose nests their own burrows can scarcely be distinguished. Their economy does not seem to demand the exercise of so much of a true reasoning power and pliable instinct as characterizes bees, such as the Honey and Humble bee, which possess a high architectural skill. Moreover they are not social; they have no part in rearing and caring for their young, a fact that lends so much interest to the history of the Hive and Humble bee. In this respect they are far below the wasps, a family belonging next below in the system of Nature. A glance at the drawing (Fig. 28), of a burrow, with its side galleries, of the Andrena vicina, reveals the economy of one of our most common forms. Quite early in spring, when the sun and vernal breezes have dried up the soil, and the fields exchange their rusty hues for the rich green verdure of May, our Andrena, tired of its idle life among the blossoms of the willow, the wild cherry, and garden flowers, suddenly becomes remarkably industrious, and wields its spade-like jaws and busy feet with a strange and unwonted energy. Choosing some sunny, warm, grassy bank (these nests were observed in the "great pasture" of Salem), not always with a southern exposure however, the female sinks her deep well through the sod from six inches to a foot into the sandy soil beneath. She goes to work literally tooth and nail. Reasoning from observations made on several species of wasps, and also from studying the structure of her jaws and legs, it is evident that she digs in and loosens the soil with her powerful jaws, and then throws out the dirt with her legs. She uses her fore legs like hands, to pass the load of dirt to her hind legs, and then runs backward out of her hole to dump it down behind her. Mr. Emerton tells me that he never saw a bee in the act of digging but once, and then she left off after a few strokes. He also says, "they are harmless and inoffensive. On several occasions I have lain on the grass near their holes for hours, but not one attempted to sting me; and when taken between the fingers, they make but feeble resistance." [Illustration: Fig. 28. Nest (natural size) of Andrena vicina, showing the main burrow, and the cells leading from it; the oldest cell containing the pupa (_a_) is situated nearest the surface, while those containing the larva (_b_) lie between the pupa and the cell (_e_) containing the pollen mass and egg resting upon it. The most recent cell (_f_) is the deepest down, and contains a freshly deposited pollen mass. At _c_ is the beginning of a cell; _g_, level of the ground.]