That aphides excrete a sweet, viscid, honey-like fluid, which affords food for many species of ants, has been long known to naturalists. Any one can convince himself of this truth if he will but put himself to the trouble of examining the leaves or branchlets of any plant at the proper season of the year. Scattered upon the foliage and tender twigs thereof will be found millions of aphides, and close beside them countless ants, that ever and anon will be seen to caress, by means of their antennæ, the little creatures for the sweets within their bodies. It has even been asserted that some species of ants keep aphides as human beings do cows, but this by the many has been doubted, or deemed imaginary. When a young man the writer was disposed to drift with the popular opinion in this particular, but a few facts that fell under his notice whilst searching for carabi and other beetles that live under stones and decayed logs, changed the bias of his mind and established in him the idea that with one species of ant this was at least the case. It was on an occasion while exploring a neighboring thicket for the objects of his search, that he discovered, underneath a large flat stone which he had raised, a nest of a small red ant, which he took to be the _Lasius flavus_ of the books. The ground was covered all over with pits, and divers communicating roads, and round about were hundreds of ants, larvæ in various stages of development, pupæ and eggs, and innumerous flocks of a white aphis, all of which were being tenderly cared for by a large army of thoughtful nurses. [Illustration: NEST OF LASIUS. Neuters About Their Work.] No sooner did the intrusion occur than the colony was a scene of busy activity. Interested in what was before him, the writer seated himself upon a small mound overlooking the nest, where could be clearly observed the minutest details of ant-life. The neuters were everywhere to be noticed, but not a single male or female ant. All the work devolved upon the neuters. These were divided into three sets, each set having a definite part to perform in the unexpected drama before it. Some neuters had the exclusive charge of the mature larvæ, others of the pupæ and very young grubs, and the rest of their aphidian herds. But it is to those that had the care of the aphides that we shall particularly invite attention. At the time of the disturbance, these specialized neuters were busy milking their cows, which they did by rubbing their long, pliant feelers against the anal nipples of the latter, drawing therefrom, as it seemed, a drop of the coveted fluid with each antennal stroke. No aphis was known to be visited in this business twice in succession, but the ants would go from one to another, and only return to the first when sufficient time had elapsed for the replenishing of its store. So intent were they upon their task, that several minutes must have passed before they took in the danger to which they were exposed.