We have seen that these Bees are not generally miners, who themselves dig out the foundation of their cells.

They make use of the old structures of others, or else of natural retreats, such as hollow stems, the spirals of empty shells and various hiding-places in walls, clay or wood.

Their work is confined to repairs to the house, such as partitions and covers.

There are plenty of these retreats; and the insects would always find first-class ones if it thought of going any distance to look for them.

But the Osmia is a stay-at-home: she returns to her birthplace and clings to it with a patience extremely difficult to exhaust.