How to Out-think a Fly

New Zealand Listener, Volume 36, Issue 922, 12 April 1957, Page 18

How to Out-think a Fly

By

MUSCICAPA

N Y daughter is going*’to be a genius at catching flies. Besides having had the advantage of training in my technique, she appears frequently to be faster than the fly. I have seen her-and other small children-pick a fly gently off the wall by the wings, with the fly making no attempt to escape. Possibly it did not realise so small a thing was a hand. An adult, who does not possess this phenomenal speed, must recognise that the fly is faster than his hand. He must understand that the fly watches his hand descend with amused tolerance until it is within half an inch before deciding it is time to get to hell out of it. To beat the fly, with its superior speed, the human being must try to out-think it. A superior technique must be employed, and I have spent a long time perfecting one. First, I have nothing to do with sprays and insect bombs. I feel the same way about them as a keen fisherman feels about using dynamite to catch trout. On the same ground I do not favour using a rolled-up newspaper, though I admit its effectiveness where so many flies have to be cleared from the room in order to enjoy a peaceful evening that more subtle methods would be too time-con- . suming. The principle of the rolled newspaper of course, is the principle of the lever. The hand travels at its ordinary speed, a matter of derision to the fly, but the end of the newspaper travels much faster. Though the fly can still get clear, he has

to decide much more quickly whether it is time to move off. After long experience of the fly’s thinking processes I have come to the conclusion that the fly’s mental agility is not equal to his speed of flight. An interesting variation of the rolled newspaper trick is the use of a springy ruler. The fly will suffer this harmless looking object to be approached to within a couple of inches. If one end of the ruler is held firmly in the left fist and the other end tensed delicately with the top of the right forefinger and suddenly released above the fly, the speed of the unflexing ruler is much greater than the take-off speed of the fly. The result is effective, spectacular, but messy. The trick of catching flies in flight with one hand I have lost. Under-thirty speed and sharpness of eye is called for. One has to estimate the trajectory of the fly and swing the arm in a wide arc to meet the fly at its estimated position when the arm has completed its swing: Then there is the difficulty of disposing of the fiy which, unhurt but astonished, is struggling ticklishly within the closed fist. It is quite easy to lose the fly at this stage but for sheer satisfaction of conquest the method is to be commended. For catching flies by hand there are three other techniques. (1) The direct slap-down upon a hard, flat object-this is messy and not very effective. Get the hand cautiously '

to within six inches of the fly, and keep it poised steadily while you study the fly. If it is motionless it has noticed you and is nutting out the situation. It is almost useless to bring the hand sharply down at this stage. The fly will easily beat it, and you will only hurt your hand. It is essential to wait until the fly starts to clean its face or amble across the hard surface. Then it is no longer poised for take-off; isn’t thinking about you at all for that matter, and chances of success are about 50 per cent. (2) The oblique stroke: the right hand is curved ready to close. It is moved in the same plane as the settled fly, and towards the fly’s head. One gains

nothing by approaching from the fly’s rear end -it can see behind it. By approaching from the front something is gained because the fly apparently cannot take off so fast backwards. This method is particularly successful when the fly is settled on a curtain or other resilient object against which the fly cannot, or should not be squashed. With this method, the fly is, of course, captured alive, and the problem of getting it out of. your closed fist without losing it is one to which I have found no very satisfactory solution. (3) The handclap method: the two hands are approached to each other in a gentle and re-

assuring manner until they are about a foot apart and two inches above the plane on which the fly is settled. This is a charming method, because the fly actually takes off, but flies directly between the approaching hands. It never seems to have the sense to scuttle sideways, or just sit still, which would render it quite safe. If these methods are used judiciously for some time, and if a few survivors are allowed to go out and spread the news, flies will tend to get cold feet and avoid your place. The Department of Health has particularly asked me to tell you to wash your hands thoroughly after a successful fly hunt.