Other species are no less destructive to the sugar plantations, either by settling in the interior of the stalks or by undermining the roots so that the plant becomes sickly and dies. The Saüba or Coushie (_Œcodoma cephalotes_), a species of ant distinguished by its large head, is the most formidable enemy of the banana and cassava plantations. Such are its numbers that in a very short time it will strip off the leaves of an entire field. Even where their nest is a mile distant from a plantation, these arch depredators know how to find it, and soon form a highway, about half a foot broad, on which they keep up the most active communications with the object of their attack. In masterly order, side by side, one army is seen to move onwards towards the field, while another is returning to the nest. In this last column each individual carries a round piece of leaf, about the size of a sixpence, which is held by one of its edges. If the distance is too great, a party meets the weary carriers half way, and relieves them of their load. Although innumerable ants may thus be moving along, yet none of them will ever be seen to be in the other’s way; and all goes on with the regularity of clock-work. A third party is no less actively employed on the scene of destruction, cutting out circular pieces of the leaves, which, as soon as they drop upon the ground, are immediately seized by the attentive and indefatigable carriers. Neither fire nor water can prevent them from proceeding with their work. Though thousands may be killed, yet in less than an hour all the bodies will have been removed. Should the highway be closed by an insurmountable obstacle, another is soon laid out, and after a few hours the operations, momentarily disturbed, resume their former activity. The use of the leaves is to thatch the curious domelike edifices which these indefatigable builders raise over their burrows, and to prevent the loose earth from falling in. Some of these domes are of gigantic dimensions, measuring two feet in height and forty feet in diameter-- a prodigious size when compared with the puny proportions of the tiny architects that raise them. Division of labour is carried on to a wonderful extent in these buildings, for the labourers who fetch the leaves do not place them, but merely fling them down on the ground, when they are picked up by a relay of workers who lay them in their proper order. As soon as they have been properly arranged they are covered with small pellets of earth, and in a very short time they are quite hidden by their earthy covering. From these domes cylindrical shafts lead down into the mysterious recesses of the burrows, whose subterranean galleries are so vast and complicated that they have never been fully investigated. Some idea of their extent may be formed from the fact that sulphur smoke having been blown into a nest, one of the outlets was detected at a distance of seventy yards.