ANTS, THEIR GUESTS AND THEIR LODGERS
The number of insects of different kinds which live in ants' nests, either as scavengers, stray visitors who have found a lodging for the moment, as guests carefully taken care of and appreciated by the ants, or as lodgers, either tolerated or hostile to their hosts and persecuted, and parasites, is very great. The most interesting of these from the ordinary observer's point of view are the true guests and the lodgers. The true guests are carefully attended to by the ants; they include such insects as the Aphides or plant lice, and others which the ants use as "cows" to secure the saccharine juices which they can obtain from them, and also certain strange beetles which have tufts of golden hairs on their body, which the ants lick—on account of what E. Wasmann[[2]] calls the etherealized oil
given off by them. These beetles are fairly numerous and belong to several quite distinct families; the one which perhaps is amongst the most interesting is a creature called Lomechusa strumosa. This insect has rather an interesting history in connexion with our British fauna. It used to be considered as an indigenous insect, but so many years passed without any one finding it, that the old records were suspected as doubtful, and it was removed from the list of British species. In 1906, however, it was rediscovered near Woking in a nest of Formica sanguinea ([pl. A], 1, 2, 3), one of the large red ants, by Mr. H. Donisthorpe. The life-history of Lomechusa is a very curious one: it is taken great care of by the ants, and its larvæ are even placed by them with their own, on which it feeds. Its numbers are kept down apparently by the overzeal of the ants to take care of them. The ants bring their own pupæ up frequently to obtain light and air and with them it brings up the Lomechusa pupæ—this seems not to suit the latter and results in the death of many of them. It is a most interesting case of how a due balance can be maintained, and what might prove an enemy
kept in his proper place by kind intentions. There are also in ants' nests what Dr. Wasmann calls "tolerated lodgers"; these are mostly creatures which are supposed to escape the notice of the ants, either by their small size or by their slow, lethargic, or on the other hand very rapid movements—these in many cases act as scavengers, living on the dead bodies of insects, etc., brought in by the ants.
The hostile lodgers are real enemies to the ants and devour their brood, and in consequence they are always at war with each other. These creatures generally resemble the ants considerably in form and colour and especially in their movements.
Besides these lodgers there are numerous parasites of the ants, such as mites, etc., so that an ant colony is a very wonderful mixture of diverse inhabitants. The distinctions given above as to the habits of the various lodgers are not always kept up, as, in some, two or more of these habits are combined. The whole study of ants and their guests is a most fascinating one: many of the latter are great rarities and much sought after by collectors. Unfortunately, the great
drawback in collecting them is the havoc caused to the nests of the ants. These structures have been the result of enormous labour on the part of these little creatures, and one cannot regard their destruction without sincere regret. I think any one who, when collecting beetles, disturbs a large nest of the little garden ant (Lasius niger) or the little yellow ant (Lasius flavus) by turning over a stone, as the writer has often done himself, must have experienced a like regret at having broken up all the beautiful passages and galleries which the ants have constructed so carefully.