f 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.]

To enter somewhat into detail, we gather from the observations of Mr.
Emerton (who has carefully watched the habits of these bees through
several seasons) the following account of the economy of this bee: On
the 4th of May the bees were seen digging their holes, most of which
were already two inches deep, and one, six inches. The mounds of earth
were so small as to be hardly noticed. At this time an Oil beetle was
seen prowling about the holes. The presence of this dire foe of Andrena
at this time, it will be seen in a succeeding chapter on the enemies of
the bees, is quite significant. By the 15th of May, hundreds of Andrena
holes were found in various parts of the pasture, and at one place, in a
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