To check the ravages of the Coffee-bug, _Lecanium coffea_, Walker, which for several years was devastating some of the plantations of Ceylon, the experiment was made of introducing the Red-ants, _Formica smaragdina_, Fab., which feed greedily on the Coccus.[542] But the remedy threatened to be attended with some inconvenience, for, says Tennent, the Malabar coolies, with bare and oiled skins, were so frequently and fiercely assaulted by the Ants as to endanger their stay on the estates. The pupæ or cocoons of the Ants, during the day, are placed near the surface of the Ant-hills to obtain heat, which is indispensable to the growth of the inclosed insects. This is taken advantage of in Europe to collect the cocoons in large quantities as food for nightingales and larks. The cocoons of a species of Wood-ant, _Formica rufa_, are the only kind chosen. In most of the towns of Germany, one or more individuals make a living during summer by this business alone. “In 1832,” says a contributor to the Penny Encyclopedia, “we visited an old woman at Dottendorf, near Bern, who had collected for fourteen years. She went to the woods in the morning, and collected in a bag the surfaces of a number of Ant-hills where the cocoons were deposited, taking Ants and all home to her cottage, near which she had a small tiled shed covering a circular area, hollowed out in the center, with a trench full of water around it. After covering the hollow in the center with leafy boughs of walnut or hazel, she strewed the contents of her bag on the level part of the area within the trench, when the Nurse-ants immediately seized the cocoons, and carried them into a hollow under the boughs. The cocoons were thus brought into one place, and after being from time to time removed, and black ones separated by a boy who spread them out on a table, and swept off what were bad with a strong feather, they were ready for market, being sold for about 4_d._ or 6_d._ a quart. Considerable quantities of these cocoons are dried for winter food of birds, and are sold in the shops.”[543] Ants not only furnish food to man for his birds, but also food for himself, in both the pupa and imago states. Nicoli Conti, who traveled in India in the early part of the fifteenth century, says the Siamese eat a species of Red-ant, of the size of a small crab, which they consider a great delicacy seasoned with pepper.[544] At the present day, the pupæ of a species of Ants are a costly luxury with these people. They are not much larger than grains of sand, and are sent to table curried, or rolled in green leaves, mingled with shreds or very fine slices of fat pork.[545] And in the province of Michuacan, Mexico, is a singular species of Ant, which carries on its abdomen “a little bagful of a sweet substance, of which the children are very fond: the Mexicans suppose this to be a kind of honey collected by the insect; but Clavigero thinks it rather its eggs.”[546]