Possibly, however, the smooth galleries or chambers of some of the larger ants might expose these _Myrmicophilæ_ to such a catastrophe, though, for my part, I suppose that the antennæ are used in some other special way which is of far more importance to their owners. The relations existing between the ants and these curious beetles has not yet been fully made out. It is true that the various species of _Paussidæ_ have upon some part of their bodies a smooth downy substance—a _pubescence_, to use the word dear to entomologists—which in other ants’-nest beetles is known to exude a sweet honey-like dew which the ants, not unnaturally, are very fond of, and for which they assiduously lick them. As they have also been seen to lick their _Paussi_, we seem, here, to have at least the root of the matter, nor does the fact that, at other times, when perhaps these have ceased to supply the attraction, they pay little attention to them, seem of much importance, since we are all neglected when we have given what we have to give. But there are other circumstances not of so straightforward a nature. It has been lately discovered by a French observer—M. Péringuey—that these _Paussidæ_, welcome guests as they generally are, will yet, sometimes, eat the larvæ of the ants with whom they live, when any small worker is engaged in carrying them from one place to another. The ants resent this, and occasionally a large one, who feels himself equal to the undertaking, will attack and even kill a _Paussus_ that he sees behaving in such a manner. Yet, with all this, so valued are these beetles by the ants that they often drag them back into their nests, when they have approached, or emerge from, the entrance. On such occasions, and also when the ants attack and even dismember them, the _Paussidæ_ make no sort of resistance. Yet they are extremely well able to do so, being armed with a weapon of tremendous efficiency, by which in a moment they could kill or stun a whole crowd of ants round about them. For they are bombardier beetles, having the power at any moment of discharging a fluid of a highly acrid nature, and so volatile that, on coming in contact with the air, it explodes with a puff of blue smoke, exhaling at the same time a very pungent and unpleasant odour. When they are tickled with a straw, even, this bombardment at once takes place, and ants all round are seen to stagger or drop to the earth. Small workers are killed, large ones retreat in confusion; yet the owner of this deadly battery, which can only have been developed for the express purpose of overwhelming an enemy, will not, even to save life or limb, discharge it against an ant—not one, at least, to whom it stands in these somewhat doubtful relations.