From Mr L Prior:

Re: Why are flies so hard to swat? Chalk it up to good planning (Aug. 28): Fascinating study you published into the take-off procedure of flies. I was surprised and amused by the omission in this article of any mention of the Fly’s blind spot.

Approaching a fly from almost any angle with a hand primed to flick the fly into the middle of next week, will always result in the fly taking flight before you have got within six inches of it; But if you approach the fly from a position approximately 45 degrees above the front of its head, and swooping centrally between its eyes, the fly has a blind spot between the two domed multiple-angle eyes and can’t see you - either that or it becomes mesmerized by not understanding what is happening.

You can get within flicking distance (ie an inch or so) of the fly and if you don’t mind a mess on your finger, you can swat it the natural way like a Chameleon’s tongue ! I’ve demonstrated this a few times, not that I like killing insects but flies do need controlling in the height of summer and sometimes when you haven’t got a swat to hand, you can use the blind spot technique and another one bites the dust.

Clearly the fly doesn’t prepare itself for take off when you use the 45 degree effect - it remains grounded and leg-chocks firmly applied!

Mr L Prior
SW England