CHAPTER IV
Ant parasites—Fleet-footed brigands—Honey-stealing mites—A strange table companion—Privileged cockroaches—Ants and their riders—A fly-ride on beetle-back.
LEAVING the beetles—though as there are probably some thousands that live habitually in ants’ nests, we have said very little about them—we may glance at an extraordinary little creature, in appearance something like a wood-louse with a fish’s tail, that resides with certain ants on the footing of a freebooter, constantly stealing from them, and eluding their resentment by extreme activity, living, as it were, in a state of perpetual motion. The legs of these persistent yet withal timid brigands are many and long, which, together with their shape and general lightness of build, enables them to run with great speed, so that they easily outdistance the ants, and, escaping to some less frequented part of the nest, with which they are always well acquainted, remain there quiet for a time. Should a single ant approach them, however, they immediately run away, or, if forced by circumstances to be near one or more—which, in an ants’ nest, must be often difficult to avoid—make a point, apparently, of never keeping still, as though to confuse them, or, perhaps, to be the better able to dash off at any instant.
AN INSECT FREEBOOTER, AND AN INSECT BEGGAR.
The extraordinary looking insect shown towards the top is the lepismid, or fleet-foot, who lives by stealing food from ants when they are in the act of passing it from one to the other. The atemeles beetle shown below is begging food, which will not be refused, from the ant in front of him.
The way in which these fleet-foots secure their food is highly remarkable, each little theft—which has about it more of the parasite than the brigand—occasioning a group of three. The ants upon which they live are of the species known as Lasius umbratus, and, like many other kinds, often feed one another, the hungry asking of the full, by whom he is rarely, if ever, denied. In the process of regurgitation—with which we are now familiar—the two stand fronting each other, with mandibles interlocked, and a drop of honey passes from mouth to mouth. For an instant it trembles between the two, resting on both, and that instant is the opportunity of the Lepismid. Darting forward, he interposes his own, and having absorbed some portion of the drop in transitu, speeds swiftly away to make a third elsewhere. Such a life, however great may be the thief’s agility, is full of danger, and, from time to time, an individual is captured and killed. In nests under observation such executions may be witnessed, and Lepismid corpses—or, as various professors prefer calling them, cadavers—are sometimes noted. Under artificial conditions, however, opportunities of escape are much more limited, unless, indeed, some special provision is made. Thus, when Professor Wheeler first introduced a colony of Lasius umbratus into one of his formicariums, he found, after a couple of dies,[[12]] five Lepismid cadavers. But having, by the addition to the said formicarium of a refugium, or asylum, made it more as in natura, this mortality ceased, and the remaining Lepismids continued henceforth existentes.