One day, bang! The tight cover resounded like the skin of a drum. Perhaps an oak had dropped an acorn on the umbrella. Presently, one after the other, bang, bang, bang! Can some practical joker have come to disturb my solitude and fling acorns or little pebbles at my umbrella? I leave my tent and inspect the neighbourhood: nothing! The same sharp sound is repeated. I look up at the ceiling, and the mystery is explained. The Bembex of the vicinity, who all consume Gad-flies, had discovered the rich provender that was keeping me company and were impudently penetrating my shelter to seize the Flies on the ceiling. Things were going to perfection: I had only to sit still and look. Every moment a Bembex would enter, swift as lightning, and dart up to the silken ceiling, which resounded with a sharp thud. Some rumpus was going on aloft, where the eye could no longer distinguish between attacker and attacked, so lively was the fray. The struggle did not last for an appreciable time: the Wasp would retire forthwith with a victim between her legs. The dull herd of Gad-flies, at this sudden irruption which slaughtered them one after the other, drew back a little all round, without quitting the treacherous shelter. It was so hot outside! Why get excited? Obviously, this suddenness of attack, followed by the swift removal of the prey, does not allow the Bembex to regulate her dagger-play. The sting no doubt performs its office, but it is directed without precision at those spots which the hazards of the fight place within its reach. I have seen Bembex, to finish off their half-killed Gad-flies still struggling in the assassin’s grasp, munch the head and thorax of the victims. This habit in itself proves that the Wasp wants a genuine corpse and not a paralysed prey, since she ends the Fly’s agony with so little ceremony. All things considered, therefore, I think that, on the one hand, the nature of the prey, which dries up so quickly, and, on the other hand, the difficulty of making such rapid attacks, explain why the Bembex serve up dead prey to their larvæ and consequently cater for them from day to day.