Other wasps are social, and, like the bees and ants, dwell together in communities. They live for one season, dying in autumn, except some of the females, which hibernate, awake in the spring, and form new colonies. These, however, do not, under ordinary circumstances, live through a second winter. One specimen which I kept tame through one spring and summer lived until the end of February, but then died. The larvæ of wasps are fat, fleshy, legless grubs. When full-grown they spin for themselves a silken covering, within which they turn into chrysalides. The oval bodies which are so numerous in ants’ nests, and which are generally called ants’ eggs, are really not eggs, but cocoons. Ants are very fond of the honey-dew which is formed by the Aphides, and have been seen to tap the Aphides with their antennæ, as if to induce them to emit some of the sweet secretion. There is a species of Aphis which lives on the roots of grass, and some ants collect these into their nests, keeping them, in fact, just as we do cows. Moreover, they collect the eggs in the autumn and tend them through the winter (when they are of no use) with the same care as their own, so as to have a supply of young Aphides in the spring. This is one of the most remarkable facts I know in the whole history of animal life. One species of red ant does no work for itself, but makes slaves of a black kind, which then do everything for their masters. The slave makers will not even put food into their own mouths, but would starve in the midst of plenty if they had not a slave to feed them. I found, however, that I could keep them in life and health for months if I gave them a slave for an hour or two in a week to clean and feed them. Ants also keep a variety of beetles and other insects in their nests. Some of these produce a secretion which is licked by the ants as they do the honey-dew; there are others, however, which have not yet been shown to be of any use to the ants, and yet are rarely, if ever, found, excepting in ants’ nests. That the ants have some reason for tolerating their presence seems clear, because they readily attack any unwelcome intruder; but what that reason is, we do not yet know. If these insects are to be regarded as the domestic animals of the ants, then we must admit that the ants possess more domestic animals than we do.