galleries, does very nearly the same: she takes shelter in the
galleries, but with her head at the entrance. Once those old
habitations are in use, however, and the building of new cells begun,
she selects another retreat. In the harmas (The piece of enclosed
waste ground on which the author studies his insects in their natural
state. Cf. "The Life of the Fly": chapter 1.--Translator's Note.), as
I have said elsewhere, are stone heaps, intended for building the
surrounding wall. This is where my Chalicodomae pass the night. Piled
up promiscuously, both sexes together, they sleep in numerous
companies, in crevices between two stones laid closely one on top of
the other. Some of these companies number as many as a couple of
hundred. The most common dormitory is a narrow groove. Here they all
huddle, as far forward as possible, with their backs in the groove. I
see some lying flat on their backs, like people asleep. Should bad
weather come on, should the sky cloud over, should the north-wind
whistle, they do not stir out.

With all these things to take into consideration, I cannot expect my
dot on the Bee's thorax to last any length of time. By day, the
constant brushing and the rubbing against the partitions of the
galleries soon wipe it off; at night, things are worse still, in the
narrow sleeping-room where the Mason-bees take refuge by the hundred.
After a night spent in the crevice between two stones, it is not
advisable to trust to the mark made yesterday. Therefore, the counting
of the number of Bees that return to the nest must be taken in hand at
once; tomorrow would be too late. And so, as it would be impossible
for me to recognize those of my subjects whose dots had disappeared
during the night, I will take into account only the Bees that return
on the same day.