Among the curious things we meet with in the woods are large heaps of earth and sand, sometimes by the roadside, and sometimes extending quite across the path, making the pedestrian ascend and descend, (a pleasing variety in this flat country,) and looking just as if some “Pará and Peru direct Railway Company” had commenced operations. These mounds are often thirty or forty feet long, by ten or fifteen wide, and about three or four feet high; but instead of being the work of a lot of railway labourers, we find it is all due to the industry of a native insect, the much-dreaded Saüba ant. This insect is of a light-red colour, about the size of our largest English species, the wood-ant, but with much more powerful jaws. It does great injury to young trees, and will sometimes strip them of their leaves in a single night. We often see, hurrying across the pathways, rows of small green leaves; these are the Saübas, each with a piece of leaf cut as smoothly as with scissors, and completely hiding the body from sight. The orange-tree is very subject to their attacks, and in our garden the young trees were each planted in the centre of a ring-shaped earthen vessel, which being filled with water completely surrounded the stem, preventing the ants from reaching it. Some places are so infested by them that it is useless planting anything. No means of destroying them are known, their numbers being so immense, as may readily be seen from the great quantities of earth they remove. Many different kinds of wasps’ and bees’ nests are constantly met with; but we were rather shy of meddling with them. They are generally attached to the undersides of leaves, especially of the young Tucumá palm, which are broad, and offer a good shelter. Some are little flat domes, with a single small opening; others have the cells all exposed. Some have only two or three cells, others a great number. These are all of a delicate papery substance; but some have large cylindrical nests, on high trees, of a material like thick cardboard. Then again there are nests in hollow trees, and others among their roots in the earth, while the solitary species make little holes in the paths, and pierce the mud-walls of the houses, till they appear as if riddled with shot. Many of these insects sting very painfully; and some are so fierce, that on their nests being approached, they will fly out and attack the unwary passer-by. The larger kinds of wasps have very long stings, and can so greatly extend their bodies that we were often stung when endeavouring to secure them for our collections.