I have said that the narrow tubes of my apparatus are, for the most part, only very incompletely colonized.

The Bee, after lodging a small number of males in them, hastens to leave them.

In the wide front gallery she can stay where she is and still be able to turn round easily for her different manipulations; she will avoid those two long journeys backwards, which are so exhausting and so bad for her wings.
Another reason no doubt prompts her not to make too great a use of the narrow passage, in which she would establish males, followed by females in the part where the gallery widens.

The males have to leave their cells a couple of weeks or more before the females.

If they occupy the back of the house they will die prisoners or else they will overturn everything on their way out.