A few Ammophilæ strike me as very busy: suppose we follow one of them, more active than the rest. I detect her giving a last sweep of the rake to her burrow, on the smooth, hard path, before introducing her caterpillar, which, already paralysed, must have been abandoned by the huntress, for the time being, a few yards away from the home. The cave is pronounced spick and span, the doorway deemed sufficiently wide to admit a bulky prey; and the Ammophila sets off in search of her captive. She finds it easily. It is a Grey Worm, lying on the ground; and the Ants have already invaded it. This prize, for which the Ants contend with her, is scorned by the huntress. Many predatory Wasps, who temporarily leave their prisoner to go and complete the burrow, or even to begin it, lodge their game high up, on a tuft of verdure, to place it beyond the reach of plunderers. The Ammophila is familiar with this prudent practice; but perhaps she has omitted to take the precaution, or else the heavy prize has fallen to the ground, and now the Ants are tugging in eager rivalry at the sumptuous fare. To drive away those pilferers is impossible: for one sent to the right-about, ten would return to the attack. So the Wasp seems to think; for, realizing the invasion, she resumes her hunting, without indulging in useless strife. The quest takes place within a radius of ten yards from the nest. The Ammophila explores the soil on foot, little by little, without hurrying; she lashes the ground continually with her antennæ curved like a bow. The bare soil, the pebbly bits, the grassy parts are visited without distinction. For nearly three hours, in the heat of the sun, in sultry weather which means rain to-morrow and a few drops to-night, I watch the Ammophila’s search, without taking my eyes from her for a second. What a difficult thing a Grey Worm is to find, for a Wasp who needs it just at that moment! It is no less difficult for man. The reader knows my method of witnessing the surgical operation to which a Hunting Wasp subjects her prey, with a view to giving her grubs flesh that is lifeless but not dead. I rob the marauder of her spoil and, in exchange, give her a live prey, similar to her own. I was arranging the same manœuvre with regard to the Ammophila, so that, after she had smitten her caterpillar, which she was bound to find at any moment now, I might make her perform the operation a second time. I was therefore in urgent need of a few Grey Worms. Favier was there, gardening. I called out to him: ‘Come here, quick; I want some Grey Worms!’