work of the Saubas, being the outworks, or domes, which overlie
and protect the entrances to their vast subterranean galleries.
On close examination, I found the earth of which they are
composed to consist of very minute granules, agglomerated without
cement, and forming many rows of little ridges and turrets. The
difference in colour from the superficial soil of the vicinity is
owing to their being formed of the undersoil, brought up from a
considerable depth. It is very rarely that the ants are seen at
work on these mounds; the entrances seem to be generally closed;
only now and then, when some particular work is going on, are the
galleries opened. The entrances are small and numerous; in the
larger hillocks it would require a great amount of excavation to
get at the main galleries; but, I succeeded in removing portions
of the dome in smaller hillocks, and then I found that the minor
entrances converged, at the depth of about two feet, into one
broad, elaborately-worked gallery or mine, which was four or five
inches in diameter.

This habit of the Sauba ant, of clipping and carrying away
immense quantities of leaves, has long been recorded in books on
natural history. When employed on this work, their processions
look like a multitude of animated leaves on the march. In some
places I found an accumulation of such leaves, all circular
pieces, about the size of a sixpence, lying on the pathway,
unattended by ants, and at some distance from any colony. Such
heaps are always found to be removed when the place is revisited
the next day. In course of time I had plenty of opportunities of
seeing them at work. They mount the tree in multitudes, the
individuals being all worker-minors. Each one places itself on
the surface of a leaf, and cuts, with its sharp scissor-like