In many parts of the Brazilian campos or savannahs the termite-hills, which are there generally of a more flattened form, are so numerous that one is almost sure to meet with one of them at the distance of every ten or twenty paces. The great ant-bear digs deep holes into their sides, where afterwards small owls build their nests. Similar termite structures, of a dark-brown colour, and a round form, are attached to the thick branches of the trees, and you will scarcely meet with a single specimen of the tall candelabra-formed cactuses (_Cerei_), so common on those high grass-plains, that is not loaded with their weight. In spite of their working in the dark, in spite of their subterranean tunnels, their strongholds, and the fecundity of their queens, the termites, even when their swarms do not expose themselves to the dangers already mentioned, are subject to the attacks of innumerable foes--ant-eaters, birds, and a whole host of insects--that do man no little service by keeping them within bounds. One of their most ferocious enemies is a species of black ant, which, on the principle of setting one thief to catch another, is used by the negroes of Mauritius for their destruction. When they perceive that the covered ways of the termites are approaching a building, they drop a train of syrup as far as the nearest encampment of the hostile army. Some of the black ants, attracted by the smell and taste of their favourite food, follow its traces and soon find out the termite habitations. Immediately part of them return to announce the welcome intelligence, and after a few hours a black army, in endless columns, is seen to advance against the white-ant stronghold. With irresistible fury (for the poor termites are no match for their poisonous sting and mighty mandibles) they rush into the galleries, and only retreat after the extirpation of the colony. Mr. Baxter (‘Eight Years’ Wanderings in Ceylon’) once saw an army of black ants returning from one of these expeditions. Each little warrior bore a slaughtered termite in his mandibles, rejoicing no doubt in the prospect of a quiet dinner-party at home. Even man is a great consumer of termites, and they are esteemed a delicacy by the natives, both in the old and in the new world.