AS we have seen, both in this chapter and a former one, aphides are not the only insects which yield the ants honey—or something honey-sweet—and are cherished by them in consequence. There are, for instance, the coccidæ, or scale insects, as mentioned by Belt; but whilst some of this family are milked in the same way as the aphides, to which, indeed, they bear a strong resemblance, others are simply eaten, as though they were sweets. To them might be said in warning, “Make yourself all honey, and the _ants_ will swallow you,” but who can modify the nature of his own juices? Then there are the ants’-nest beetles, many of which have a sweet downiness which the ants enjoy licking, and are for this reason carried about with them when they move from one place to another. Not that they are always carried, for one little beetle, at any rate, whose name—it must be a diminutive—is _Formicoxenus nitidulus_, is accustomed to ride on the backs of its protectors, like the little cockroaches discovered by Professor Wheeler. But perhaps the most interesting parallel to the aphides, as cows, is to be found in certain caterpillars, which are as soft and defenceless as they are, and represent a class of creatures which ants habitually prey upon. A certain family of butterflies, however, commonly known as the Blues, but entitled to the scholarly name of _Lycænidæ_, produce caterpillars which bear, upon the twelfth segment of the body, a certain honey-holding reservoir which, when full or nearly so, may be made to yield its contents through the same treatment which is so effectual in the case of the aphides. The ants tap or titillate the body of the caterpillar, near where the gland is situated, with their antennæ, and the caterpillars, charmed with such affability, overflow in return. This interesting fact has been observed in various parts of the Old World, and also in North America; but the most detailed account which we have of it comes from India. In this case, as in all the others, the caterpillar is a quite small one, and feeds on the leaves of a certain tree, bearing both “an astringent yellow fruit” and the name of _Zizyphus jujuba_, though, by the way, jujubes are not, as a rule, astringent. The name of this little caterpillar—it would scorn to be behind the tree it feeds on in such a matter—is _Tarucus theophrastus_, so now we have something to fix it in the memory. The ant that patronises it is a large black one—_its_ name I cannot give—and here, too, as in the case of the aphidean relations, we have, in the most noteworthy of the actions recorded, a very remarkable instance of what looks like foresight, and foresight, too, of a very large and general kind. In the first place, the ants make a nest at the foot of the trees in which the caterpillars reside, and here, during the period of their growth and nourishment, they avail themselves of their services. But when this period is over, and the caterpillars are about to change into