No sooner is the nest wanted for the eggs which she is about to lay, than the hitherto slumbering faculty of constructiveness is awakened, and she selects the angle of the branch, or the hollow in the bank or in the wall, or the tangle of reeds, or the plat form Of twigs on the tree-top, exactly the right place for her, the selection being always the same according to her tribe, and true to the instinct which was implanted in her at the first.